A photovoltaic device includes an electrically-conductive front contact layer; an electrically-conductive back contact layer, the back contact layer being intended to be situated further from a source of incident light than the front contact layer; and a semiconductor-based PIN junction having a substantially amorphous intrinsic silicon layer sandwiched between a P-type doped semiconductor layer and an N-type doped semiconductor layer. The layer of the PIN junction situated closest to the back contact layer is a silicon-germanium alloy layer including at least 2 mol % of germanium.

A method of manufacturing a solar cell includes forming a photoelectric converter including an amorphous semiconductor layer, forming an electrode connected to the photoelectric converter, and performing a post-treatment by providing light to the photoelectric converter and the electrode, wherein, in the performing of the post-treatment, a plasma lighting system (PLS) is used as a light source, and a processing temperature is within a range from about 100 C. to about 300 C.

A photovoltaic device and method include a doped germanium-containing substrate, an emitter contact coupled to the substrate on a first side and a back contact coupled to the substrate on a side opposite the first side. The emitter includes at least one doped layer of an opposite conductivity type as that of the substrate and the back contact includes at least one doped layer of the same conductivity type as that of the substrate. The at least one doped layer of the emitter contact or the at least one doped layer of the back contact is in direct contact with the substrate, and the at least one doped layer of the emitter contact or the back contact includes an n-type material having an electron affinity smaller than that of the substrate, or a p-type material having a hole affinity larger than that of the substrate.

A photovoltaic device and method include a doped germanium-containing substrate, an emitter contact coupled to the substrate on a first side and a back contact coupled to the substrate on a side opposite the first side. The emitter includes at least one doped layer of an opposite conductivity type as that of the substrate and the back contact includes at least one doped layer of the same conductivity type as that of the substrate. The at least one doped layer of the emitter contact or the at least one doped layer of the back contact is in direct contact with the substrate, and the at least one doped layer of the emitter contact or the back contact includes an n-type material having an electron affinity smaller than that of the substrate, or a p-type material having a hole affinity larger than that of the substrate.

A photovoltaic device and method include a doped germanium-containing substrate, an emitter contact coupled to the substrate on a first side and a back contact coupled to the substrate on a side opposite the first side. The emitter includes at least one doped layer of an opposite conductivity type as that of the substrate and the back contact includes at least one doped layer of the same conductivity type as that of the substrate. The at least one doped layer of the emitter contact or the at least one doped layer of the back contact is in direct contact with the substrate, and the at least one doped layer of the emitter contact or the back contact includes an n-type material having an electron affinity smaller than that of the substrate, or a p-type material having a hole affinity larger than that of the substrate.

A film-forming method for forming a thin film on a substrate includes a contact step, an external force removal step, and a film-forming step. At the contact step (step B), the substrate 30 and a member 31 in contact with one surface of the substrate is stacked, and the substrate 30 and the member 31 in contact with one surface of the substrate are placed under vacuum while an external force is applied in a direction in which the substrate 30 and the member 31 in contact with one surface of the substrate are stacked. At the external force removal step (step C), the external force is removed at atmospheric pressure or under vacuum. At a film-forming step (step E), a thin film is formed on the one surface or the other surface of the substrate 30.

A method for fabricating a device with integrated photovoltaic cells includes supporting a semiconductor substrate on a first handle substrate and doping the semiconductor substrate to form doped alternating regions with opposite conductivity. A doped layer is formed over a first side the semiconductor substrate. A conductive material is patterned over the doped layer to form conductive islands such that the conductive islands are aligned with the alternating regions to define a plurality of photovoltaic cells connected in series on a monolithic structure.

An optoelectronic device including a crystalline semiconductor layer based on GeSn and including a pin junction. This formed semiconductor layer includes a base portion; a single-crystal intermediate portion having an average value x.sub.pi1 of proportion of tin less than x.sub.ps1, thus forming a barrier region against charge carriers flowing in an upper portion; and the single-crystal upper portion including a homogeneous medium with a proportion of tin x.sub.ps1, and vertical structures having an average value x.sub.ps2 of proportion of tin greater than x.sub.ps1, thus forming regions for emitting or for receiving infrared radiation.

Textured transparent layers are formed on the incident light receiving surface of thin film solar cells to increase their efficiency by altering the incident light path and capturing a portion of the light reflected at the MLA. The textured transparent layer is an array of lenses of micrometer proportions such as hemispheres, hemi-ellipsoids, partial-spheres, partial-ellipsoids, cones, pyramids, prisms, half cylinders, or combinations thereof. A method of forming the textured transparent layer to the light incident surface of the solar cell is by forming an array of lenses from a photocurable resin and its subsequent curing. The photocurable resin can be applied by inkjet printing or can be applied by roll to roll imprinting or stamping with a mold.

An exemplary embodiment of the present invention provides an optical sensor, including: a substrate; an infrared ray sensing thin film transistor including a first semiconductor layer that is formed on the substrate and arranged to operate by receiving infrared light, and a bandpass filter formed on the substrate and sized and arranged to pass the infrared light; a visible ray sensing thin film transistor including a second semiconductor layer formed on the substrate and arranged to operate by receiving visible light; and a switching thin film transistor including a third semiconductor layer formed on the substrate, wherein the bandpass filter may be formed of a metal material patterned to have features, successive features spaced apart from each other by a predetermined period so as to pass the infrared light and to block the visible light.