The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component comprising at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

A photovoltaic device includes a first contact and a hybrid absorber layer. The hybrid absorber layer includes a chalcogenide layer and a semiconductor layer in contact with the chalcogenide layer. A buffer layer is formed on the absorber layer, and a transparent conductive contact layer is formed on the buffer layer.

Disclosed herein are solar cells with kesterite-based absorbers that hold promise as a low-cost and durable technology to renewably produce electricity using solar energy conversion. The current state-of-the-art (SOA) for such kesterite solar cells is Cu.sub.2ZnSn(S,Se).sub.4 and novel materials are required to suppress the formation bandgap-fluctuation- and charge-carrier-recombination-inducing defects and eventually to achieve solar cell efficiencies higher than the SOA. Three important material properties that govern the efficiency of a solar cell are the concentrations of performance-degrading defects, band gap, and chemical stability. Disclosed here is a stable material, specifically Cu.sub.2CdGe(S,Se).sub.4, as a new candidate that can exhibit higher defect formation energies than Cu.sub.2ZnSnS.sub.4 and a nearly optimal bandgap, which can eventually result in higher solar-cell efficiencies in solar energy conversion.

A method for forming a photovoltaic device comprising the steps of: providing a first conductive material on a substrate; depositing a continuous layer of a dielectric material less than 10 nm thick on the first conductive material; annealing the first conductive material and the layer of dielectric material; forming a chalcogenide light-absorbing material on the layer of dielectric material; and depositing a second material on the light-absorbing material such that the second material is electrically coupled to the light-absorbing material; wherein the first conductive material and the dielectric material are selected such that, during the step of annealing, a portion of the first conductive material undergoes a chemical reaction to form: a layer of a metal chalcogenide material at the interface between first conductive material and the dielectric material; and a plurality of openings in the layer of dielectric material; the openings being such to allow electrical coupling between the light-absorbing material and the layer of a metal chalcogenide material. Additionally contemplated is a photovoltaic device formed by this method.

Methods of making a semiconductor layer from nanocrystals are disclosed. A film of nanocrystals capped with a ligand can be deposited onto a substrate; and the nanocrystals can be irradiated with one or more pulses of light. The pulsed light can be used to substantially remove the ligands from the nanocrystals and leave the nanocrystals unsintered or sintered, thereby providing a semiconductor layer. Layered structures comprising these semiconductor layers with an electrode are also disclosed. Devices comprising such layered structures are also disclosed.

The present invention relates to a method for planarizing a CIS-based thin film, the method including: electropolishing a CIS-based compound layer by applying current or voltage to an electrochemical cell including: a CIS-based compound layer provided on a conductive base material, as a working electrode; a counter electrode; and an electrolyte solution including a precursor of elements constituting the CIS-based compound layer, a supporting electrolyte, a complexing agent, and an additive including a hydroxy functional group.

The invention concerns a mirror (14), in particular for a photovoltaic cell (10), comprising a stack of layers (SC1, SC2, SC3, SC4, SC5, SC6), the layers (SC1, SC2, SC3, SC4, SC5, SC6) being superimposed along a stacking direction, the stack comprising: a first layer (SC1) of transparent conductive oxide, a second optical reflection layer (SC4) of metal, and a third layer (SC6) of conductive oxide.

A voltage-matched solar module for converting incident solar radiation into electricity consisting of a plurality of wafer-sized multi-junction solar devices and wiring circuitry adjacent to a module-sized bottom substrate. Each solar device has at least two photovoltaic (PV) cells separated by electrically insulating transparent layers. The PV cells are aligned so as to overlap and are electrically connected to the wiring circuitry by conducting vias. The wiring circuitry includes a multiplicity of serial strings electrically connected in parallel and having substantially the same voltage. A method of producing the solar module is disclosed which utilizes an ALD/LPCVD tool for van der Waals epitaxy of 2D materials.

A photovoltaic device comprises a PIN structure in which a p-type hole transporting layer (2) is carried by a substrate (1) and a perovskite layer (3) and an n-type electron transporting layer (4) are arranged in sequence on the p-type layer. A light transmissive electrically conductive layer (9) is provided on top of the n-type electron transporting layer to form a light receiving top surface. Between the n-type electron transporting layer and the light transmissive conductive layer there is provided a structure comprising two inorganic electrically insulative layers (6, 8) having a layer of a conductive material (7) therebetween, wherein the two inorganic electrically insulative layers comprise a material having a band gap of greater than 4.5 eV and the layer of a conductive material comprises a material having a band gap of less than the band gap of the electrically insulative layers, wherein each electrically insulative layer forms a type-1 offset junction with the layer of conductive material.

Photovoltaic structures having multiple absorber layers separated by a diffusion barrier are provided. In one aspect, a method of forming an absorber on a substrate includes: depositing a first layer of light absorbing material on the substrate; depositing a diffusion barrier; depositing a second layer of light absorbing material on the diffusion barrier, wherein the first layer of light absorbing material has a different band gap from the second layer of light absorbing material; and annealing the absorber, wherein the diffusion barrier prevents diffusion of elements between the first layer of light absorbing material and the second layer of light absorbing material during the annealing. A solar cell and method for formation thereof are also provided.