Some embodiments of vacuum electronics call for nanoscale field-enhancing geometries. Methods and apparatus for using nanoparticles to fabricate nanoscale field-enhancing geometries are described herein. Other embodiments of vacuum electronics call for methods of controlling spacing between a control grid and an electrode on a nano- or micron-scale, and such methods are described herein.

A method of fabricating an Ag(Cu)InGaSe (A(C)IGS) based thin film using SeAg.sub.2Se core-shell nanoparticles, an A(C)IGS based thin film fabricated by the method, and a tandem solar cell having the A(C)IGS thin film are disclosed. More particularly, a method of fabricating a densified Ag(Cu)InGaSe (A(C)IGS) based thin film by non-vacuum coating a substrate with a slurry containing SeAg.sub.2Se core-shell nanoparticles, an A(C)IGS based thin film fabricated by the method, and a tandem solar cell including the A(C)IGS based thin film are disclosed. According to the present invention, an A(C)IGS based thin film including Ag is manufactured by applying SeAg.sub.2Se core-shell nanoparticles in a process of manufacturing a (C)IGS thin film, thereby providing an A(C)IGS based thin film having a wide band gap.

A solar cell module comprising: a first protective member having a curved surface having a prescribed radius of curvature set in at least a first direction; a first filling material arranged upon the first protective member; a plurality of solar cell strings arranged in the first direction upon the first filling material and connected in parallel to each other; a second filling material arranged upon the solar cell strings; and a second protective member arranged upon the second filling material. The solar cell strings have connected in series a plurality of solar cells that are arranged in a second direction. The solar cells have end cross-sections along at least the first direction that have a waveform shape.

A solid-state imaging device in which a pixel circuit formed on the first surface side of a semiconductor substrate is shared by a plurality of light reception regions and second surface side of the semiconductor substrate is the light incident side of the light reception regions. The second surface side regions of the light reception regions are arranged at approximately even intervals and the first surface side regions of the light reception regions e are arranged at uneven intervals. Respective second surface side regions and first surface side regions are joined in the semiconductor substrate so that the light reception regions extend from the second surface side to the first surface side of the semiconductor substrate.

A single-step wet etch process is provided to isolate multijunction solar cells on semiconductor substrates, wherein the wet etch chemistry removes semiconductor materials nonselectively without a major difference in etch rate between different heteroepitaxial layers. The solar cells thus formed comprise multiple heterogeneous semiconductor layers epitaxially grown on the semiconductor substrate.

The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

A Ge-on-Si photodetector constructed without doping or contacting Germanium by metal is described. Despite the simplified fabrication process, the device has responsivity of 1.24 A/W, corresponding to 99.2% quantum efficiency. Dark current is 40 nA at 4 V reverse bias. 3-dB bandwidth is 30 GHz.

A semiconductor light receiving device includes a substrate, a semiconductor fine line waveguide provided on the substrate, and a light receiving circuit that is provided on the substrate and that absorbs light propagating through the semiconductor fine line waveguide. The light receiving circuit includes a p type first semiconductor layer, a number of second semiconductor mesa structures provided on the p type first semiconductor layer in such a manner that an n type second semiconductor layer is provided on top of an i type second semiconductor layer, a p side electrode connected to the p type first semiconductor layer in a location between the second semiconductor mesa structures, and an n side electrode connected to the n type second semiconductor layer. The refractive index and the optical absorption coefficient of the second semiconductor layers are greater than the refractive index and the optical absorption coefficient of the first semiconductor layer.

Provided are a nanostructure and an optical device including the nanostructure. The nanostructure is formed on a two-dimensional material layer such as graphene and includes nanopatterns having different shapes. The nanopatterns may include a first nanopattern and a second nanopattern and may be spherical; cube-shaped; or poly-pyramid-shaped, including a triangular pyramid shape; or polygonal pillar-shaped.

A method comprises providing a cavity structure on the substrate comprising a first growth channel extending in a first direction, a second growth channel extending in a second direction, wherein the second direction is different from the first direction and the second channel is connected to the first channel at a channel junction, a first seed surface in the first channel, at least one opening for supplying precursor materials to the cavity structure, selectively growing from the first seed surface a first semiconductor structure substantially only in the first direction and in the first channel, thereby forming a second seed surface for a second semiconductor structure at the channel junction, growing in the second channel the second semiconductor structure in the second direction from the second seed surface, thereby forming the semiconductor junction comprising the first and the second semiconductor structure.