A semiconductor substrate, including a back surface having N-type conductive regions and P-type conductive regions. The N-type conductive regions are provided with first non-pyramidal texture structures, and the P-type conductive regions are provided with second non-pyramidal texture structures. A top surface of the first non-pyramidal texture structure is a polygonal plane, and a top surface of the second non-pyramidal texture structure is a polygonal plane. A one-dimensional size of the top surface of the first non-pyramidal texture structure is less than a one-dimensional size of the top surface of the second non-pyramidal texture structure. The one-dimensional size of the top surface of the first non-pyramidal texture structure is in a range of 5 m to 12 m. The one-dimensional size of the top surface of the second non-pyramidal texture structure is in a range of 10 m to 40 m.

The photodetector is formed in a silicon carbide body formed by a first epitaxial layer of an N type and a second epitaxial layer of a P type. The first and second epitaxial layers are arranged on each other and form a body surface including a projecting portion, a sloped lateral portion, and an edge portion. An insulating edge region extends over the sloped lateral portion and the edge portion. An anode region is formed by the second epitaxial layer and is delimited by the projecting portion and by the sloped lateral portion. The first epitaxial layer forms a cathode region underneath the anode region. A buried region of an N type, with a higher doping level than the first epitaxial layer, extends between the anode and cathode regions, underneath the projecting portion, at a distance from the sloped lateral portion as well as from the edge region.

Certain embodiments of the present invention may be directed to a transistor structure. The transistor structure may include a semiconductor substrate. The semiconductor substrate may include a drift region, a collector region, an emitter region, and a lightly-doped/undoped region. The lightly-doped/undoped region may be lightly-doped and/or undoped. The transistor structure may also include a heterostructure. The heterostructure forms a heterojunction with the lightly-doped/undoped region. The transistor structure may also include a collector terminal. The collector terminal is in contact with the collector region. The transistor structure may also include a gate terminal. The gate terminal is in contact with the heterostructure. The transistor structure may also include an emitter terminal. The emitter terminal is in contact with the lightly-doped/undoped region and the emitter region.

Various particular embodiments include a method for forming a photodetector, including: forming a structure including a barrier layer disposed between a layer of doped silicon (Si) and a layer of germanium (Ge), the barrier layer including a crystallization window; and annealing the structure to convert, via the crystallization window, the Ge to a first composition of silicon germanium (SiGe) and the doped Si to a second composition of SiGe.

A unit pixel element that acts as an image sensor or a solar cell according to the present invention comprises a photo detector that drives a photocurrent flow, induced by light incident onto the gate, along the channel between the source and the drain; a first switch that is wired and switched on or switched off between the source terminal of the photo detector and the first solar cell bus; and a second switch that is wired and switched on or switched off between the gate terminal of the photo detector and the second solar cell bus, and features a function of light energy harvesting and high-efficiency photoelectric conversion that generates and supplies effective electric power.

A unit pixel element that acts as an image sensor or a solar cell according to the present invention comprises a photo detector that drives a photocurrent flow, induced by light incident onto the gate, along the channel between the source and the drain; a first switch that is wired and switched on or switched off between the source terminal of the photo detector and the first solar cell bus; and a second switch that is wired and switched on or switched off between the gate terminal of the photo detector and the second solar cell bus, and features a function of light energy harvesting and high-efficiency photoelectric conversion that generates and supplies effective electric power.

A unit pixel element that acts as an image sensor or a solar cell according to the present invention comprises a photo detector that drives a photocurrent flow, induced by light incident onto the gate, along the channel between the source and the drain; a first switch that is wired and switched on or switched off between the source terminal of the photo detector and the first solar cell bus; and a second switch that is wired and switched on or switched off between the gate terminal of the photo detector and the second solar cell bus, and features a function of light energy harvesting and high-efficiency photoelectric conversion that generates and supplies effective electric power.

A photovoltaic device and method include forming a plurality of pillar structures in a substrate, forming a first electrode layer on the pillar structures and forming a continuous photovoltaic stack including an N-type layer, a P-type layer and an intrinsic layer on the first electrode. A second electrode layer is deposited over the photovoltaic stack such that gaps or fissures occur in the second electrode layer between the pillar structures. The second electrode layer is wet etched to open up the gaps or fissures and reduce the second electrode layer to form a three-dimensional electrode of substantially uniform thickness over the photovoltaic stack.

To provide an imaging device equipped with a photodiode, which is capable of enhancing both of a capacity and sensitivity. In an area of a P-type well in which a photodiode is formed, a P-type impurity region is formed from the surface of the P-type well to a predetermined depth. Further, an N-type impurity region is formed to extend to a deeper position. N-type impurity regions and P-type impurity regions respectively extending in a gate width direction from a lower part of the N-type impurity region to a deeper position so as to contact the N-type impurity region are alternately arranged in a plural form along a gate length direction in a form to contact each other.

A unit pixel element that acts as an image sensor or a solar cell according to the present invention comprises a photo detector that drives a photocurrent flow, induced by light incident onto the gate, along the channel between the source and the drain; a first switch that is wired and switched on or switched off between the source terminal of the photo detector and the first solar cell bus; and a second switch that is wired and switched on or switched off between the gate terminal of the photo detector and the second solar cell bus, and features a function of light energy harvesting and high-efficiency photoelectric conversion that generates and supplies effective electric power.