A homogeneous coating solution for forming a light-absorbing layer of a solar cell, the homogeneous solution including: at least one metal or metal compound selected from the group consisting of a group 11 metal, a group 13 metal, a group 11 metal compound and a group 13 metal compound; a Lewis base solvent; and a Lewis acid.

A method for manufacturing a large-area thin film solar cell includes the steps of: (a) forming a first contact layer on a substrate; (b) forming a multi-layer metal precursor film on the first contact layer, which includes the sub-steps of (b1) sputtering a first multinary metal precursor layer on the first contact layer, the first multinary metal precursor layer containing Cu, Ga and KF, and (b2) sputtering an In-containing precursor layer on the first multinary metal precursor layer; and (c) subjecting the multi-layer metal precursor film to selenization to form an absorber layer having a chalcopyrite phase.

A photovoltaic device includes one or more features that taken alone or in combination enhance its efficiency. Some embodiments may comprise a tandem solar device in which a top PV cell is fabricated upon a front transparent substrate, that also serves as the top encapsulating substance. The top PV cell including the front encapsulating substance is then bonded (e.g., using adhesive) to a bottom PV cell in order to complete the tandem device. Using the same transparent, insulating element as both front encapsulating substance and a substrate for fabricating the top PV cell, obviates to the need to provide a separate structure (with resulting interfaces) to perform the latter role. For tandem and non-tandem PV devices, a Through-Substrate-Via (TSV) structure may extend through an insulating substrate in order to provide contact with an opposite side (e.g., back electrode). Embodiments may find particular use in fabricating shingled perovskite photovoltaic solar cells.

Disclosed are a precursor for preparing a light absorption layer of a solar cell including (a) an aggregate-phase composite including a first phase including a copper (Cu)-tin (Sn) bimetallic metal and a second phase including zinc (Zn)-containing chalcogenide, or including the first phase including a copper (Cu)-tin (Sn) bimetallic metal, the second phase including zinc (Zn)-containing chalcogenide and a third phase including copper (Cu)-containing chalcogenide; or (b) core-shell structured nanoparticles including a core including copper (Cu)-tin (Sn) bimetallic metal nanoparticles and a shell including zinc (Zn)-containing chalcogenide, or the zinc (Zn)-containing chalcogenide and copper (Cu)-containing chalcogenide; or (c) a mixture thereof, and a method of preparing the same.

A method for fabricating thin-film optoelectronic devices (100), the method comprising: providing a alkali-nondiffusing substrate (110), forming a back-contact layer (120); forming at least one absorber layer (130) made of an ABC chalcogenide material, adding least one and advantageously at least two different alkali metals, and forming at least one front-contact layer (150) wherein one of said alkali metals comprise Rb and/or Cs and where, following forming said front-contact layer, in the interval of layers (470) from back-contact layer (120), exclusive, to front-contact layer (150), inclusive, the comprised amounts resulting from adding alkali metals are, for Rb and/or Cs, in the range of 500 to 10000 ppm and, for the other alkali metals, typically Na or K, in the range of 5 to 2000 ppm and at most ½ and at least 1/2000 of the comprised amount of Rb and/or Cs. The method (200) is advantageous for more environmentally-friendly production of photovoltaic devices on flexible substrates with high photovoltaic conversion efficiency and faster production rate.

Sputtered zinc oxide layer is used to improve and control the crystalline properties of a molybdenum back contact used in photovoltaic cells. Optimum thicknesses for the zinc oxide layer are identified.

Techniques for electrodepositing selenium (Se)-containing films are provided. In one aspect, a method of preparing a Se electroplating solution is provided. The method includes the following steps. The solution is formed from a mixture of selenium oxide; an acid selected from the group consisting of alkane sulfonic acid, alkene sulfonic acid, aryl sulfonic acid, heterocyclic sulfonic acid, aromatic sulfonic acid and perchloric acid; and a solvent. A pH of the solution is then adjusted to from about 2.0 to about 3.0. The pH of the solution can be adjusted to from about 2.0 to about 3.0 by adding a base (e.g., sodium hydroxide) to the solution. A Se electroplating solution, an electroplating method and a method for fabricating a photovoltaic device are also provided.

A method to fabricate thin-film photovoltaic devices including a photovoltaic Cu(In,Ga)Se.sub.2 or equivalent ABC absorber layer, such as an ABC.sub.2 layer, deposited onto a back-contact layer characterized in that the method includes at least five deposition steps, during which the pair of third and fourth steps are sequentially repeatable, in the presence of at least one C element over one or more steps. In the first step at least one B element is deposited, followed in the second by deposition of A and B elements at a deposition rate ratio A.sub.r/B.sub.r, in the third at a ratio A.sub.r/B.sub.r lower than the previous, in the fourth at a ratio A.sub.r/B.sub.r higher than the previous, and in the fifth depositing only B elements to achieve a final ratio A/B of total deposited elements.

A thin-film solar cell comprising a substrate, a first electrode layer arranged upon the substrate, a p-type light absorption layer formed by a group I-III-IV.sub.2 compound arranged upon the first electrode layer, and an n-type second electrode layer arranged upon the p-type light absorption layer. The p-type light absorption layer includes Cu as a group 1 element and includes Ga and In as group III elements. The ratio of the atomic number between Cu and the group III elements in the entire p-type light absorption layer is lower than 1.0; the ratio of the atomic number between Ga and the group III elements in the surface on the second electrode layer side is no more than 0.13; and the ratio of the atomic number between Cu and the group III elements in the surface on the second electrode layer side is at least 1.0.

A photoelectric conversion element having a photoelectric conversion layer formed between a first electrode layer and a second electrode layer, in which the photoelectric conversion layer contains Cu and Ag, which are Group I elements, In and Ga, which are Group III elements, and Se and S, which are Group VI elements. A portion at which a minimum value of a band gap appears in a thickness direction of the photoelectric conversion layer is included in the intermediate region. When a ratio of a mole amount of Ag to a sum of mole amounts of the Group I elements other than Ag, the Group III elements, and the Group VI elements is defined as an Ag concentration, a portion at which a maximum value of the Ag concentration appears in the thickness direction of the photoelectric conversion layer is included in the intermediate region.