A method includes depositing spacers at a plurality of locations directly on a back contact layer over a solar cell substrate. An absorber layer is formed over the back contact layer and the spacers. The absorber layer is partially in contact with the spacers and partially in direct contact with the back contact layer. The solar cell substrate is heated to form voids between the absorber layer and the back contact layer at the locations of the spacers.

An imaging device which offers an image with high quality and is suitable for high-speed operation is provided. The imaging device includes a first region to an n-th region (n is a natural number of 2 or more and 16 or less) each including a first circuit, a second circuit, a third circuit, and a fourth circuit. The first to third circuits each include a transistor in which silicon is used in an active layer or an active region. The fourth circuit includes a photoelectric conversion element and a transistor in which an oxide semiconductor is used in an active layer. The first circuit includes a region overlapping with the fourth circuit. The third circuit includes a region overlapping with the fourth circuit.

A method (200) for fabricating patterns on the surface of a layer of a device (100), the method comprising: providing at least one layer (130, 230); adding at least one alkali metal (235); controlling the temperature (2300) of the at least one layer, thereby forming a plurality of self-assembled, regularly spaced, parallel lines of alkali compound embossings (1300, 1305) at the surface of the layer. The method further comprises forming cavities (236, 1300) by dissolving the alkali compound embossings. The method (200) is advantageous for nanopatterning of devices (100) without using templates and for the production of high efficiency optoelectronic thin-film devices (100).

A solar cell according to embodiments of the inventive concept includes a back electrode on a substrate, a first light absorbing layer including gallium (Ga) and indium (In) on the back electrode, a first buffer layer on the first light absorbing layer, a first window layer on the first buffer layer, a second light absorbing layer including

Ga on the first window layer, a second buffer layer on the second light absorbing layer, and a second window layer on the second buffer layer, wherein a composition ratio of (Ga)/(Ga+In) of the first light absorbing layer is lower than that of the second light absorbing layer.

A solar cell according to the embodiment includes a plurality of back electrode patterns spaced apart from each other on a substrate; a light absorption layer including contact patterns to connect electrodes to each other and division patterns to divide cells into unit cells on the substrate formed with the back electrode patterns; top electrode patterns spaced apart from each other by the division patterns on the light absorption layer; and insulating patterns among the back electrode patterns or on the back electrode patterns. The top electrode patterns are filled in the contact patterns and electrically connected to the back electrode patterns.

A method for forming a photovoltaic device includes forming an absorber layer with a granular structure on a conductive layer; conformally depositing an insulating protection layer over the absorber layer to fill in between grains of the absorber layer; and planarizing the protection layer and the absorber layer. A buffer layer is formed on the absorber layer, and a top transparent conductor layer is deposited over the buffer layer.

Solar cell element with a carrier (14), a thin film layer structure on a surface of the carrier, the thin film layer structure comprises a transparent first electrode layer (20), active layers (22, 23) in which a portion of the energy of the incident light is absorbed and a second electrode layer (24), the thin film layer structure has a light reflecting rear boundary surface, and the surface of said carrier (14) comprises at least two planar surface regions that close and angle with and form continuation of each other so that between them a recess is formed, and a portion of light reflected from the rear boundary surface of a first surface region will pass through the recess to fall on the second surface region and generates additional charge carriers therein, and the thin film structure on the surface regions constitutes a uniform uninterrupted thin film structure, wherein the extent of absorption of the thin film structure in the visible spectral region of light is at most 90% of the energy of the incident light. A plurality of the solar cell elements forms a solar cell arrangement, in which the carrier (14) is common for all cell elements and a surface of the carrier (14) has a plurality of juxtaposed pyramid-like recesses on which the thin film layers are provided.

A method for post-treating an absorber layer for photoelectric conversion of incident light into electric current. The method includes providing a chalcogen-containing absorber layer on a carrier, applying a post-treatment layer on a surface of the absorber layer, wherein the post-treatment material is not a buffer or component of a buffer, and thermally diffusing the post-treatment material into the absorber layer. A method for producing a layer system for the production of thin-film solar cells is also described.

A system for manufacture of I-III-VI-absorber photovoltaic cells involves sequential deposition of films comprising one or more of silver and copper, with one or more of aluminum indium and gallium, and one or more of sulfur, selenium, and tellurium, as compounds in multiple thin sublayers to form a composite absorber layer. In an embodiment, the method is adapted to roll-to-roll processing of photovoltaic cells. In an embodiment, the method is adapted to preparation of a CIGS absorber layer having graded composition through the layer of substitutions such as tellurium near the base contact and silver near the heterojunction partner layer, or through gradations in indium and gallium content. In a particular embodiment, the graded composition is enriched in gallium at a base of the layer, and silver at the top of the layer. In an embodiment, each sublayer is deposited by co-evaporation of copper, indium, gallium, and selenium, which react in-situ to form CIGS. In a particular embodiment, a special selenium or tellurium source, valve and delivery subsystem is made of quartz, graphite, coated graphite, or molybdenum. In a particular embodiment, an ion-beam source module configured for surface smoothing the solar absorber sublayer surface before passing through the final deposition zone.

A preparation method of the light absorption layer of a copper-indium-gallium-sulfur-selenium film solar cell is provided. The method employs a non-vacuum liquid-phase chemical technique, which comprises following steps: forming source solution containing copper, indium, gallium, sulfur and selenium; using the solution to form a precursor film on a substrate by a non-vacuum liquid-phase process; drying and annealing the precursor film. Thus, a compound film of copper-indium-gallium-sulfur-selenium is gained.