SEMICONDUCTOR DEVICES BEING EXPOSED TO RADIATION
20220028571 · 2022-01-27
Assignee
Inventors
Cpc classification
H01L31/02161
ELECTRICITY
H01L31/022408
ELECTRICITY
G21H1/06
PHYSICS
International classification
Abstract
Disclosed herein is a device that includes at least one functional semiconductor element; and static electric field source(s) associated with the at least one functional semiconductor element, the static electric field source(s) comprising at least one electret component and having a heterogeneous charge distribution. Also disclosed herein is a device includes a functional semiconductor element; a static electric field source comprising at least one electret element, the static electric field source imparting a static electric field to the functional semiconductor element; and at least one nuclear radiation source for continuously imparting nuclear beta radiation to the at least one electret element and/or the functional semiconductor element. Use of at least a radioactive beta source for replenishing charge in an electret, as well as use of at least a radioactive beta source for simultaneously replenishing charge in an electret and modifying charge mobility of a semiconductor material, are also disclosed. A nuclear battery includes at least one functional semiconductor element; at least one radiation source imparting nuclear radiation to the at least one functional semiconductor element; and at least one electret imparting a static electric field to the at least one functional semiconductor element.
Claims
1. A device comprising: at least one functional semiconductor element; and a static electric field source associated with the at least one functional semiconductor element, the static electric field source comprising at least one electret component and having a heterogeneous charge distribution.
2. The device of claim 1, the at least one electret component comprises at least one electret component having a heterogeneous charge distribution.
3. The device of claim 2, wherein the at least one electret component having a heterogeneous charge distribution has a charge distribution pattern.
4. The device of claim 3, wherein the charge distribution pattern comprises at least one charged region and at least one uncharged or lesser charged region.
5. The device of claim 4, wherein each of the at least one charged region has a heterogeneous charge distribution.
6. The device of claim 5, wherein the heterogeneous charge distribution of each of the at least one charged region comprises a greater charge at the interior of the charged region than at the periphery of the charged region.
7. The device of claim 3, wherein each of the at least one charged region is adjacent to a respective one of the functional semiconductor elements.
8. The device of claim 7, wherein there are a plurality of charged regions.
9. The device of claim 8, wherein the plurality of charged regions have the same charge magnitude.
10. The device of claim 8, wherein the plurality of charged regions include at least one charged region having a different charge strength than at least one other charged region.
11. The device of claim 3, wherein the charge distribution pattern comprises at least one negatively charged region and at least one positively charged region.
12. The device of claim 11, wherein the at least one negatively charged region and at least one positively charged region are located on opposite sides of the device to increase collection of electronics from a depletion region of the device.
13. The device of claim 11, wherein each of the at least one positively charged region has a heterogeneous charge distribution.
14. The device of claim 13, wherein the heterogeneous charge distribution of each of the at least one positively charged region comprises a greater positive charge at the interior (center?) of the positively charged region than at the periphery of the positively charged region.
15. The device of claim 11, wherein each of the at least one positively charged region is aligned with a respective one of the semiconductor elements in the array.
16. The device of claim 11, wherein each of the at least one negatively charged regions has a heterogeneous charge distribution.
17. A device comprising: a functional semiconductor element; a static electric field source comprising at least one electret element, the static electric field source imparting a static electric field to the functional semiconductor element; and at least one nuclear radiation source for continuously imparting nuclear radiation to the at least one electret element and/or the functional semiconductor element.
18. The device of claim 17, wherein a first of the at least one electret element is associated with a positive electrode of the functional semiconductor element.
19. The device of claim 18, wherein the at least one nuclear radiation source is associated with the positive electrode of the functional semiconductor element.
20. The device of claim 18, wherein the at least one nuclear radiation source is associated with a negative electrode of the functional semiconductor element.
21. The device of claim 18, wherein the at least one nuclear radiation source is associated with the positive electrode and a negative electrode of the functional semiconductor element.
22. The device of claim 17, wherein a first of the at least one electret element is associated with a negative electrode of the functional semiconductor element.
23. The device of claim 22, wherein the at least one nuclear radiation source is associated with a positive electrode of the functional semiconductor element.
24. The device of claim 22, wherein the at least one nuclear radiation source is associated with the negative electrode of the functional semiconductor element.
25. The device of claim 22, wherein the at least one nuclear radiation source is associated with a positive electrode and the negative electrode of the functional semiconductor element.
26. The device of claim 17, wherein the static electrical field source comprises at least two electret elements.
27. The device of claim 26, wherein: a first of the at least two electret elements is associated with a positive electrode of the functional semiconductor element; and a second of the at least two electret elements is associated with a negative electrode of the functional semiconductor element.
28. The device of claim 27, wherein the at least one nuclear radiation source is associated with the positive electrode of the functional semiconductor element.
29. The device of claim 27, wherein the at least one nuclear radiation source is associated with the negative electrode of the functional semiconductor element.
30. The device of claim 27, wherein the at least one nuclear radiation source is associated with both the positive electrode and the negative electrode of the functional semiconductor element.
31. The device of claim 27, wherein the first and the second of the at least two electret elements impart electric fields of different strengths.
32. The device of claim 27, wherein the first and the second of the at least two electret elements impart electric fields with different orientations.
33. The device of claim 17, wherein the functional semiconductor element is selected from the group consisting of: a PN junction diode, a Schottky diode, a photovoltaic diode, a light-emitting diode (LED), a Zener diode, an avalanche diode, a varactor diode, a tunnel diode, and a laser diode.
34. The device of claim 17, wherein: the functional semiconductor element and the static electric field source are integrated, and the at least one nuclear radiation source is separable from the functional semiconductor element and the static electric field source.
35. The device of claim 17, wherein the functional semiconductor element, the static electric field source, and the at least one nuclear radiation source are integrated.
36. The device of claim 17, wherein the at least one nuclear radiation source is arranged with respect to the at least one electret to reduce or increase energy of charged particles traversing the semiconductor material.
37. The device of claim 17, wherein the at least one nuclear radiation source is arranged with respect to the at least one electret to decrease the charge of the at least one electret.
38. The device of claim 17, wherein the at least one nuclear radiation source further imparts at least one of: alpha particles, proton, triton, muon, recoil mass, x-rays, gamma rays, and energetic photons to the at least one electret element and/or the functional semiconductor element.
39. Use of at least a radioactive source for replenishing charge in an electret.
40. The use of claim 39, wherein the radioactive source is a radioactive beta source.
41. Use of at least a radioactive source for simultaneously replenishing charge in an electret and modifying charge mobility of a semiconductor material.
42. The use of claim 41, wherein the radioactive source is a radioactive beta source.
43. A nuclear battery comprising: at least one functional semiconductor element; at least one radiation source imparting nuclear radiation to the at least one functional semiconductor element; and at least one electret imparting a static electric field to the at least one functional semiconductor element.
44. The nuclear battery of claim 43, wherein the at least one electret imparts a homogenous electric field to the at least one functional semiconductor element.
45. The nuclear battery of claim 43, wherein the at least one electret imparts a heterogeneous electric field to the at least one functional semiconductor element.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] Embodiments of the invention will now be described with reference to the appended drawings in which:
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DETAILED DESCRIPTION
[0089] In this description, an electret material is incorporated into the design, construction, and electrical structure of radiation detectors, nuclear batteries, or photoelectric devices. In one embodiment, the electret material is in the form of a film. Such an electret film functions provides a quasi-permanent electric field that increases or expands the effective charge collection region within these devices without the need of a power source. Ionizing radiation or photoelectric induced charges induced in the charge collection region are more efficiently collected at the device electrodes with the presence of the electric field supplied by the electret, providing an unpowered alternative to systems that incorporate actively powered voltage bias. The static, quasi-permanent electric field created by the electret more effectively separates radiation-induced free electrons from the positively charged sites in the device and increases the transport of the electrons to the electrode without the need for an active power source. By enhancing the collection volume region and the charge separation efficiency of electron-hole pairs generated by the radiation passing into and through the devices, the available induced electrical current of the device is increased for storage or work functions.
[0090] One benefit of incorporating an electret into the structural design of a device such as a detector, nuclear battery, or photoelectric device is a measurable increase in electrical charge that can be collected by the device electrodes in response to external radiation incident on the device. The improved charge collection efficiency has significant implications for increasing available electric current to power devices, since less radiation is required to product equivalent power. Furthermore, as compared with alternative approaches involving actively powered devices, benefits include reduced weight of the device, and reduced cost of production relative to power produced.
[0091] Other benefits to the semi-permanent electric field producing a bias voltage include increasing electron mobility speed, increasing the efficiency of electron collection in response to applied ionizing radiation, and enlarging the volume in the device within which electrons can be efficiently directed to a device electrode.
[0092] In this description, devices influenced by the semi-permanent electric field produced by the electret may be any one of a Schottky, PN-junction, photovoltaic or other diode types including but not limited to Zener diodes, varactor diodes, avalanche diodes, tunnel diodes, light emitting diodes (LEDs), and laser diodes.
[0093] In embodiments described and depicted herein, the electret is positioned on or in the diode structure to introduce an electrical field into at least the portion of the diode that lies between the diode electrodes. The electret may be adjoined to either or both the positive (+) and the negative (−) electrodes of the diode(s).
[0094] Furthermore, the electret may be charged prior to the construction of the device, charged after construction of the device (for example, while in place within the device or in place with respect to the device), and/or recharged after extended use of the device.
[0095] In embodiments, the electret may be recharged, increased in charge state or decreased in charge state by placement of a radioactive beta source external to the surfaces of the electret so that the beta particles enter into the electret structure.
[0096] Such a beta source may be permanently fixed, exchangeable, or temporarily affixed to the device. Such a beta source may also be combined with radioactive sources that emit other ionizing emissions, such as alpha particles, x rays, gamma rays, and/or energetic photons along with the beta particles.
[0097] Other sources of nuclear radiation than beta radiation sources may be used in conjunction with the semiconductor material, alone or in combination with the beta radiation sources. Such other radiation sources would not function to charge an electret but to cause the formation of electron-hole pairs. In some cases, the radiation particle energy will be degraded and allow maximum electron-hole pair creation at optimal location in the depleted region.
[0098] In embodiments, a radioactive beta source may be oriented with respect to the electret and the diode (or other semiconductor device) to impart radiation to change the charge state of the electret or to produce free electrons in the semiconductor device, or both simultaneously. Pure beta particle emitting isotopes of use for continuous charging of the electret during device operation include Ar-39, Ar-42, Be-10, Bi-210, Bk-249, C-14, Ca-45, Cd-113, Cd-113m, Cs-135, Cu-66, Er-169, Er-169, H-3, In-115, Kr-85, Kr-85, Ni-63, Ni-66, P-32, P-33, Pb-209, Pd-107, Pm-147, Pr-143, Pr-145, Pu-241, Re-187, Ru-106, S-35, Se-79, Si-32, Sm-151, Sn-121, Sn-123, Sr-89, Sr-90, Tc-99, Te-127, Tm-171, W-188, Y-90, and Y-91 but may include isotopes that emit mixed radiation types such as alpha-beta, alpha-x-ray, alpha-gamma, etc., and include cascading emissions of charged particles as the parent nuclide transmutes to new daughter products.
[0099] Various placements and orientations of electrets and, in respective embodiments, radiation sources, are shown in the accompanying figures.
[0100] It will be appreciated that the strength of the electrical charge of the electret may be established to aim towards optimizing the character or performance of the device. In embodiments, the negative pole of the electret is positioned proximal to a particular side of a device while the positive pole of the electret is positioned distal from that particular side. In other embodiments, the positive pole of the electret is positioned proximal to a particular side of a device while the negative pole of the electret is positioned distal from that particular side.
[0101] In embodiments involving multiple electrets (for example, two electrets or three electrets or more) being integrated with or being otherwise positioned to impart respective electric fields on to a given device, the different electrets may be configured to share the same charge strength or to have different respective charge strengths. Furthermore, the different electrets may be configured to share the same charge orientation, or have different respective charge orientations. These aspects may depend on whether the different electrets are positioned at the same or respective different faces of the device to which the electric field(s) are to be imparted.
[0102] In embodiments, the electret is a planar component. In other embodiments, the electret at least partially conforms to the surface topography of the device.
[0103] In embodiments, an electret component is configured with a material that has been conditioned to have a heterogeneous dipole strength and/or a heterogeneous orientation. This, in turn, will impart electric fields having different charge strengths and/or different charge orientations into a region of interest containing the semiconductor device or multiple devices. For example, an electret component may contain regions of zero dipole strength (generally, no particular alignment of dipoles being in the majority in a particular three-dimensional region of the electret component) and other regions of non-zero dipole strength (generally, a particular majority alignment of dipoles in a particular other three-dimensional region of the electret component). The same, or a different, electret component may contain regions of dipole charges that are majority aligned with a Z-axis through the electret component and other regions of dipole charges that are majority aligned off of the Z-axis of the electret component. The provision of a heterogeneous structure having different charge strengths and/or different charge orientations enables the electret component to, depending on the application, act on the semiconductor material in a way that directs, or “funnels”, electron-hole pairs in particular desired directions and at particular desired speeds through the semiconductor material. This may depend on at which point in, and path through, the volume of the semiconductor material the radiation is causing the electron-hole pairs to form, rather than necessarily in a single direction and at a single speed.
[0104] The particular strength and/or orientation of the electric field from a given region of the electret component may, in embodiments, be employed to slow down or resist the propagation of energy induced by radiation through the semiconductor material. For example, in some embodiments, the electret's field has a strength and/or orientation to counter or “degrade” the energy of the charged particles emitted by the radiation source that entering the semiconductor material of a diode. The energy of such charged particles can thereby be reduced to maximize the energy transfer from the particle to production of electron-hole pairs in the volume of greatest collection efficiency in the diode. For example, an electret can serve as an energy degrader where alpha emitting radioisotopes, such as Am-241, are used, thereby allowing more of the alpha particles to deposit their energy in the energy-producing diode volume.
[0105] The heterogeneous strength and/or orientation of the electret component may be patterned to enable the electret component to overlie or otherwise influence a patterned array of semiconductor components, such as an array of diodes.
[0106] In embodiment, multiple layers of electrets—a stack of electret films, for example—may be used in conjunction with one or more semiconductor devices.
[0107] The electret or electrets may be formed using a body of a single dielectric material having a uniform density, or alternatively a homogeneous or heterogeneous overall composition of multiple dielectric materials.
[0108] Radioisotope diode batteries may be stacked together such that they are all influenced by a single electret component.
[0109] In embodiments, metal surfaces on the faces of an electret may serve as one or more electrodes to the diode.
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[0114] In particular, diode 90 includes an electret 99 with its negative pole proximal to N-type semiconductor material 96. Diode 90 includes a depletion region 94 and P-type semiconductor material 92.
[0115] Diode 100 includes an electret 109 with its positive pole proximal to P-type semiconductor material 102. Diode 100 includes a depletion region 104 and N-type semiconductor material 106.
[0116] Diode 110 includes two electrets 119_1 and 119_2. The negative pole of electret 119_2 is proximal to N-type semiconductor material 116 and the positive pole of electret 119_1 is proximal to P-type semiconductor material 112 across depletion region 114 from N-type semiconductor material 116.
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[0118] In particular, diode 120 includes an electret 129 with its negative pole proximal to N-type semiconductor material 126. Diode 120 includes a depletion region 124 and P-type semiconductor material 122. Furthermore, a radiation source component R1 is positioned proximal to the P-type semiconductor component 122.
[0119] Diode 130 includes an electret 139 with its positive pole proximal to P-type semiconductor material 132. Diode 130 includes a depletion region 134 and N-type semiconductor component 136. Furthermore, a radiation source component R2 is positioned proximal to the negative pole of electret component 139.
[0120] Diode 140 includes two electrets 149_1 and 149_2. A negative pole of electret 149_2 is proximal to N-type semiconductor material 146 and a positive pole of electret 149_1 is proximal to P-type semiconductor material 142 across depletion region 144 from N-type semiconductor material 146. Furthermore, a radiation source component R3 is positioned proximal to a negative pole of electret component 149_1.
[0121] It will be appreciated that alternative combinations are possible. For example, the radiation source component may be sandwiched between an electret component and the semiconductor material. Furthermore, multiple radiation source components may be provided for a given diode, and may respectively be positioned adjacent to or proximal to the P-type and N-type semiconductor materials. In embodiments, the electret material encapsulates or is otherwise combined with the radiation source component or components.
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[0123] Solar cell 160 includes upper electrodes 168A and an electret component 169 with its negative pole proximal to N-type semiconductor material and corresponding electrode 168B.
[0124] Solar cell 170 includes electret components 179 with their positive poles proximal to P-type semiconductor material and upper electrodes 178A. Solar cell 170 also includes a lower electrode 178B.
[0125] Solar cell 180 includes electret components 189_1 with their positive poles proximal to P-type semiconductor material and upper electrodes 188A. Solar cell 180 also includes an electret component 189_2 with its negative pole proximal to N-type semiconductor material and corresponding electrode 188B.
[0126] Solar cell 190 includes electret components 199 with their positive poles immediately adjacent to P-type semiconductor material.
[0127] Solar cell 200 includes electret components 209_2 with negative poles proximal to N-type semiconductor material and corresponding electrode 208B, and electret components 209_1 with their positive poles immediately adjacent to P-type semiconductor material.
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[0129] Diode 210 includes an electret component 219 with its negative pole proximal to a lower electrode 218B and opposite diode 210 from electrode 218A.
[0130] Diode 220 includes an electret component 229 with its positive pole proximate an upper electrode 228A.
[0131] Diode 230 includes an electret component 239_2 with its negative pole proximal to a lower electrode 238B and an electret component 239_1 with its positive pole proximate an upper electrode 238A.
[0132] Diode 240 includes an electret component 249 with its negative pole proximal to a lower electrode 248B and a radiation source component R4 proximal to its upper electrode 248A.
[0133] Diode 250 includes an electret component 259 with its positive pole proximal to an upper electrode 258A and a radiation source component R5 proximal to a negative pole of electret component 259.
[0134] Diode 260 includes an electret component 269_2 with its negative pole proximal to a lower electrode 268B and an electret component 269_1 with its positive pole proximal to an upper electrode 268A, along with a radiation source component R6 proximal to a negative pole of electret component 269_1.
[0135] It will be appreciated that alternative combinations are possible. For example, the radiation source component may be sandwiched between an electret component and the semiconductor material. Furthermore, multiple radiation source components may be provided for a given diode, and may respectively be positioned adjacent to or proximal to the semiconductor material. In embodiments, electret material encapsulates or is otherwise combined with the radiation source component or components.
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[0137] Diode 270 includes an electret component 279 with its negative pole positioned adjacent to a lower electrode 278B. Diode 280 includes an electret component 289 with its positive pole positioned adjacent to and spanning across contours of an upper electrode 288A. Diode 290 includes an electret component 299_1 with its positive pole positioned adjacent to and spanning across contours of an upper electrode 298A, and an electret component 299_2 with its negative pole positioned adjacent a lower electrode 298B. Diode 300 includes an electret component 309 with its positive pole positioned adjacent to and following contours of an upper electrode 308A. Diode 310 includes an electret component 319_1 with its positive pole positioned adjacent to and following contours of an upper electrode 318A, as well as an electret component 319_2 with its negative pole positioned adjacent to a lower electrode 318B.
[0138] Diode 310 includes an electret component 329 with its negative pole positioned adjacent to a lower electrode 328B, and a radiation source component R7 positioned adjacent to and spanning across contours of an upper electrode. Diode 330 includes an electret component 339 with its positive pole positioned adjacent to and spanning across contours of an upper electrode 338A, and a radiation source component R8 positioned adjacent to a negative pole of electret component 339. Diode 340 includes an electret component 349_1 with its positive pole positioned adjacent to and spanning across contours of an upper electrode 348A, and a radiation source component R9 positioned adjacent to a negative pole of electret component 349_1. Diode 340 also includes an electret component 349_2 with its negative pole positioned adjacent to a lower electrode 348B.
[0139] Diode 350 includes an electret component 359 with its positive pole positioned adjacent to and following contours of an upper electrode 358A, and a radiation source component R10 positioned adjacent to a negative pole of electret component 359. Diode 360 includes an electret component 369_1 with its positive pole positioned adjacent to and following contours of an upper electrode 368A, and a radiation source component R11 positioned adjacent to a negative pole of electret component 369_1. Diode 360 also includes an electret component 369_2 with its negative pole positioned adjacent to a lower electrode 368B.
[0140] As can be seen, in some embodiments an electret component is positioned adjacent to an upper electrode, or adjacent to a lower electrode. In other embodiments, two electret components are positioned, respectively, adjacent to the upper electrode and the lower electrode. In some embodiments, an electret is shaped to conform (at least partially) to the non-planar surface topology of the diode thereby to follow its contour, and other electrets are planar and are either associated with a planar surface topology of the diode or associated with a non-planar surface topology of the diode thereby to span any contour. It will be appreciated that alternative combinations are possible. For example, the radiation source component may, in embodiments, be sandwiched between an electret component and the semiconductor material. Multiple radiation source components may be provided for a given diode, and may respectively be positioned adjacent to or proximal to the semiconductor material. In embodiments, electret material encapsulates or is otherwise combined with the radiation source component or components.
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[0142] As can be seen, in some embodiments, the radiation source component is planar, or multiple radiation source components are associated with a 3D Schottky diode and include a planar radiation source component and a non-planar radiation source component. In embodiments, a radiation source has a planar side and a non-planar side thereby to follow contours of an elected component and/or an upper side of the diode. Various alternatives are shown.
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[0145] It will be appreciated that, in embodiments, an electret associated with one side of the semiconductor device may be homogeneous in charge while an electret associated with another side of the semiconductor device is heterogeneous in charge. Alternatively, both electrets may be identical in their homogeneity or in their heterogeneity. Alternatively, both electrets may be different in their homogeneity or in their heterogeneity (i.e., in the magnitude, orientation, spacing etc. of their charges).
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[0149] Although embodiments have been described with reference to the drawings, those of skill in the art will appreciate that variations and modifications may be made without departing from the spirit, scope and purpose of the invention as defined by the appended claims.
[0150] For example, while PN-junction, photodiodes, Schottky diodes and solar cells are described and depicted herein as being semiconductor-based devices to which the principles described herein may be applied, the principles described herein are also applicable to other types of semiconductor devices, such as Zener diodes, varactor diodes, avalanche diodes, tunnel diodes, light-emitting diodes (LEDs), and laser diodes.
[0151] Also, while electret components having heterogeneous charge distributions therethrough have been described and depicted in association with an array of semiconductor elements, alternatives are possible in which a given electret component having a heterogeneous charge distribution is associated with a single semiconductor element.
[0152] Furthermore, while electret components having heterogeneous charge distributions therethrough have been described and depicted, alternatives are possible in which a heterogeneous electric field is imparted to a semiconductor device or an array thereof by positioning multiple discrete electret components (having their own respective uniform or heterogeneous charge distributions) having—collectively—a heterogeneous charge distribution with respect to the semiconductor device.
[0153] Furthermore, while embodiments have been described featuring only an electret or electrets as static electric field sources, alternatives are possible in which the static electric field source includes one or more electrets as well as another type of static electric field source.
[0154] In addition, while embodiments have been described that employ N-type silicon-based semiconductors, the principles herein may be applied to semiconductors formed of other materials, such as silicon carbide, gallium nitride, and perovskite compounds.
[0155] Furthermore, while embodiments described herein depict charged regions in combination with uncharged regions, alternatives are possible in which charged regions having a first magnitude are combined with charged regions having a second magnitude that is different than the first magnitude.
[0156] Furthermore, while embodiments have been described and depicted herein that employ one or more electrets of heterogeneous charge along X and/or Y dimensions, embodiments are contemplated in which the heterogeneity is also provided along the Z dimension thereby to provide the possibility of heterogeneity in any, some or all of the dimensions.
[0157] Furthermore, embodiments of nuclear batteries having electrets with heterogeneous charge distributions are contemplated along with the other forms of semiconductor devices described more specifically herein (for example, diodes). However, it should be appreciated that the present disclosure contemplates as new the combination of one or more electrets having a homogeneous charge distribution with a nuclear battery. Such a combination can provide advantages to the nuclear battery in the form of improved charge collection, improved control over the energy of the great many electron-hole pairs generated during operation of the nuclear battery (so as to increase or decrease the energy) and control over the directions through the semiconductor that electron-hole pairs traverse. Other semiconductor-based devices that, like nuclear batteries, have semiconductors being exposed to high energy radiation that penetrates deeply into the semiconductor can similarly benefit from associating the semiconductors with appropriately-positioned electret(s) having homogenous and/or heterogeneous charge distributions.