The present invention relates to a tandem solar cell which comprises: a perovskite solar cell comprising a perovskite absorption layer; a silicon solar cell placed under the perovskite solar cell; a junction layer placed between the perovskite solar cell and the silicon solar cell; an upper electrode placed on the perovskite solar cell; and a lower electrode placed under the silicon solar cell.

Photodetectors using photonic crystals (PhCs) in polysilicon film that include an in-plane resonant defect. A biatomic photodetector includes an optical defect mode that is confined from all directions in the plane of the PhC by the photonic bandgap structure. The coupling of the resonance (or defect) mode to out-of-plane radiation can be adjusted by the design of the defect. Further, a “guided-mode resonance” (GMR) photodetector provides in-plane resonance through a second-order grating effect in the PhC. Absorption of an illumination field can be enhanced through this resonance.

A solar cell can include a silicon semiconductor substrate; an oxide layer on a first surface of the silicon semiconductor substrate; a polysilicon layer on the oxide layer; a diffusion region at a second surface of the silicon semiconductor substrate; a dielectric film on the polysilicon layer; a first electrode connected to the polysilicon layer through the dielectric film; a passivation film on the diffusion region; and a second electrode connected to the diffusion region through the passivation film.

A method for preparing silicon substrate having average crystallite size greater than or equal to 20 μm, including at least the steps of: (i) providing polycrystalline silicon substrate of which average grain size is less than or equal to 10 μm; (ii) subjecting substrate to overall homogeneous plastic deformation, at temperature of at least 1000° C.; (iii) subjecting substrate to localized plastic deformation in plurality of areas of substrate, called external stress areas, spacing between two consecutive areas being at least 20 μm, local deformation of substrate being strictly greater than overall deformation carried out in step (ii); step (iii) being able to be carried out subsequent to or simultaneous to step (ii); and (iv) subjecting substrate obtained in step (iii) to recrystallization heat treatment in solid phase, at temperature strictly greater than temperature used in step (ii), in order to obtain desired substrate.

The present invention relates to a method for producing highly doped polycrystalline semiconductor layers on a semiconductor substrate, wherein a first Si precursor composition comprising at least one first dopant is applied to one or more regions of the surface of the semiconductor substrate; optionally a second Si precursor composition comprising at least one second dopant is applied to one or more other regions of the surface of the semiconductor substrate, where the first dopant is an n-type dopant and the second dopant is a p-type dopant or vice versa; and the coated regions of the surface of the semiconductor substrate are each converted, so as to form polycrystalline silicon from the Si precursor. The invention further relates to the semiconductor obtainable by the method and to the use thereof, especially in the production of solar cells.

A photo transistor and a display device employing the photo transistor are provided. The photo transistor includes a gate electrode disposed on a substrate, a gate insulating layer that electrically insulates the gate electrode, a first active layer overlapping the gate electrode and including metal oxide, wherein the gate insulating layer is disposed between the gate electrode and the active layer, a second active layer disposed on the first active layer and including selenium, and a source electrode and a drain electrode respectively electrically connected to the second active layer.

A solar cell, having a front side which faces the sun during normal operation, and a back side opposite the front side can include a silicon substrate having doped regions and a polysilicon layer disposed over the doped regions. The solar cell can include a conductive filling formed between a first metal layer and doped regions and through or at least partially through the polysilicon layer, where the conductive filling electrically couples the first metal layer and the doped region. In an embodiment, a second metal layer is formed on the first metal layer, where the first metal layer and the conductive filling electrically couple the doped regions and the second metal layer. In some embodiments, the solar cell can be a front contact solar cell or a back contact solar cell.

A silicon-on-insulator (SOI) substrate includes a silicon dioxide layer and a silicon layer. A detection region receives a detected optical mode coupled to an incident optical mode defined by an optical waveguide in the silicon layer. The detection region consists essentially of an intrinsic semiconductor material with a spacing structure surrounding at least a portion of the detection region, which comprises p-type, n-type doped semiconductor regions adjacent to first, second portions, respectively, of the detection region. A dielectric layer is deposited over at least a portion of the spacing structure. The silicon layer is located between the dielectric layer and the silicon dioxide layer. First, second metal contact structures are formed within trenches in the dielectric layer electrically coupling to the p-type, n-type doped semiconductor regions, respectively, without contacting any of the intrinsic semiconductor material of the detection region.

A phototransistor includes an emitter, a collector, and a base between the emitter and the collector. The base has a thickness greater than 500 nanometers and the base absorbs photons passing through the collector to the base.

A phototransistor includes an emitter, a collector, and a base between the emitter and the collector. The base has a thickness greater than 500 nanometers and the base absorbs photons passing through the collector to the base.