A photoelectric conversion element of an embodiment includes: a back electrode; a heterojunction-type light absorbing layer on the back electrode, containing Cu, selected from Al, In and Ga, and selected from Se and S, and having a chalcopyrite structure; a transparent electrode on the light absorbing layer, wherein aback electrode side-part of the light absorbing layer is of p-type, and a transparent electrode-side part of the light absorbing layer is of n-type, the light absorbing layer has a part with an average crystal grain size of 1,000 nm to 3,000 nm in the vicinity of the back electrode, and the light absorbing layer has apart with an average crystal grain size of at most 500 nm in the vicinity of the transparent electrode or the light absorbing layer has an amorphous part in the vicinity of the transparent electrode.

A method (200) for fabricating thin-film optoelectronic devices (100), the method comprising: providing a substrate (110), forming a back-contact layer (120); forming at least one absorber layer (130) made of an ABC chalcogenide material, adding at least one alkali metal (235), and forming at least one cavity (236, 610, 612, 613) at the surface of the absorber layer wherein forming of said at least one cavity is by dissolving away from said surface of the absorber layer at least one crystal aggregate comprising at least one alkali crystal comprising at least one alkali metal. The method (200) is advantageous for more environmentally-friendly production of photovoltaic devices (100) on flexible substrates with high photovoltaic conversion efficiency and faster production rate.

A method includes placing at least two substrates on a substrate carrier at a distance from one another, placing the substrate carrier in a reaction chamber, depositing a precursor on the at least two substrates, and performing a first annealing process on the at least two substrates. The at least two substrates include a first content of a first material. The distance between the at least two substrates is based on the first content of the first material and at least one processing parameter. The disclosed method advantageously provides for improved Na-dosing control.

A photoelectric conversion element of an embodiment includes a substrate, a transparent first electrode on the substrate, a second electrode, and a light absorbing layer of a homo-junction type interposed between the first electrode and the second electrode. The light absorbing layer includes a p-type region on the second electrode side and an n-type region on the first electrode side. The n-type region has an n-type dopant. The photoelectric conversion element has a boundary surface between the light absorbing layer on the n-type region side and the first electrode.

A method of fabricating a photovoltaic device includes forming an absorber layer comprising an absorber material above a substrate, forming a buffer layer over the absorber layer, forming a front transparent layer over the buffer layer, and exposing the photovoltaic device to heat or radiation at a temperature from about 80 C. to about 500 C. for a period of time, subsequent to the step of forming a buffer layer over the absorber layer.

Disclosed are a solar cell and a method for fabricating the same. The solar cell according to the embodiment includes a back electrode layer on a support substrate; a light absorbing layer including a glass frit having sodium on the back electrode layer; and a front electrode layer on the light absorbing layer.

A solar cell according to an embodiment includes a p-electrode, an n-electrode, a p-type light-absorbing layer provided on the p-electrode and being mainly composed of a cuprous oxide compound, an n-type layer disposed between the p-type light-absorbing layer and the n-electrode, and a compound of first metal provided between the p-type light-absorbing layer and the n-type layer. Coverage of the compound of the first metal covering the p-type light absorption layer is 10% or more and less than 100%. The first metal is one or more elements selected from the group consisting of Al, Hf, Zr, and B. The cuprous oxide compound is in direct contact with the compound of the first metal and the n-type layer.