A layer system (1) for thin-film solar cells (100), comprising an absorber layer (4), which contains a chalcogenide compound semiconductor, and a buffer layer (5), which is arranged on the absorber layer (4), wherein the buffer layer (5) has a semiconductor material of the formula A.sub.xIn.sub.yS.sub.z, where A is potassium (K) and/or cesium (Cs), with 0.015x/(x+y+z)0.25 and 0.30y/(y+z)0.45.

A bipolar solar cell includes a backside junction formed by a silicon substrate and a first doped layer of a first dopant type on the backside of the solar cell. A second doped layer of a second dopant type makes an electrical connection to the substrate from the front side of the solar cell. A first metal contact of a first electrical polarity electrically connects to the first doped layer on the backside of the solar cell, and a second metal contact of a second electrical polarity electrically connects to the second doped layer on the front side of the solar cell. An external electrical circuit may be electrically connected to the first and second metal contacts to be powered by the solar cell.

A solar cell includes a substrate; a first passivation layer on a first surface of the substrate; a first field region on the first surface of the substrate; an anti-reflection layer on the first passivation layer; a second passivation layer on a second surface of the substrate; an emitter region on the second passivation layer, the emitter region forming a p-n junction and a hetero-junction junction with the substrate; a second field region on the second passivation layer, the second field region forming a hetero-junction with the substrate; a first electrode contacted to the emitter region; a second electrode contacted to the second field region; a spacing between the emitter region and the second field region; and a third passivation layer on the second surface of the substrate at the spacing.

An optoelectronic device as well as its methods of use and manufacture are disclosed. In one embodiment, an optoelectronic device includes first and second semiconducting atomically thin layers with corresponding first and second lattice directions. The first and second semiconducting atomically thin layers are located proximate to each other, and an angular difference between the first lattice direction and the second lattice direction is between about 0.000001 and 0.5, or about 0.000001 and 0.5 deviant from of a Vicnal angle of the first and second semiconducting atomically thin layers. Alternatively, or in addition to the above, the first and second semiconducting atomically thin layers may form a Moir superlattice of exciton funnels with a period between about 50 nm to 3 cm. The optoelectronic device may also include charge carrier conductors in electrical communication with the semiconducting atomically thin layers to either inject or extract charge carriers.

Kesterite-based homojunction photovoltaic devices are provided. The photovoltaic devices include a p-type semiconductor layer including a copper-zinc-tin containing chalcogenide compound and an n-type semiconductor layer including a silver-zinc-tin containing chalcogenide compound having a crystalline structure the same as a crystalline structure the copper-zinc-tin containing chalcogenide compound.

A photoelectric conversion element includes a first electrode, a ferroelectric layer provided on the first electrode, and a second electrode provided on the ferroelectric layer, the second electrode being a transparent electrode, and a pn junction being formed between the ferroelectric layer and the first electrode or the second electrode.

Embodiments of the present disclosure are directed to infrared detector devices incorporating a tunneling structure. In one embodiment, an infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, and a tunneling structure including a barrier layer adjacent to the absorber layer and a second contact layer adjacent to the barrier layer. The barrier layer has a tailored valence band offset such that a valence band offset of the barrier layer at the interface between the absorber layer and the barrier layer is substantially aligned with the valence band offset of the absorber layer, and the valence band offset of the barrier layer at the interface between the barrier layer and the second contact layer is above a conduction band offset of the second contact layer.

The present invention relates to a photovoltaic material and a photovoltaic device comprising the photoactive material arranged between a hole transport layer and an electron acceptor layer. The present invention also relates to the use of the photovoltaic material.

One aspect of the present invention is a double sided hybrid crystal structure including a trigonal Sapphire wafer containing a (0001) C-plane and having front and rear sides. The Sapphire wafer is substantially transparent to light in the visible and infrared spectra, and also provides insulation with respect to electromagnetic radio frequency noise. A layer of crystalline Si material having a cubic diamond structure aligned with the cubic <111> direction on the (0001) C-plane and strained as rhombohedron to thereby enable continuous integration of a selected (SiGe) device onto the rear side of the Sapphire wafer. The double sided hybrid crystal structure further includes an integrated III-Nitride crystalline layer on the front side of the Sapphire wafer that enables continuous integration of a selected III-Nitride device on the front side of the Sapphire wafer.

The inventive concepts provide a solar cell and a method of fabricating the same. The method includes preparing a substrate in a chamber, forming a light absorbing layer on the substrate by setting temperature in the chamber to a first temperature and by supplying a first source into the chamber, forming a buffer layer on the substrate by setting temperature in the chamber to a second temperature lower than the first temperature and by supplying the first source into the chamber, and forming a window layer on the substrate by supplying a second source different from the first source into the chamber.