A process of forming a thin film photoactive layer of an optoelectronic device comprising: providing a substrate having a surface comprising or coated with a metal M selected from at least one of Pb, Sn, Ge, Si, Ti, Bi, or In; and converting the metal surface or metal coating of the substrate to a perovskite layer.

The present invention relates to a chalcogenide device and particularly to a metal chalcogenide device using transition metal chalcogenides as electrodes and a production method therefor. The metal chalcogenide device according to the present invention may comprise: a substrate; an oxide layer positioned on the substrate; a first conductive metal chalcogenide layer positioned on the oxide layer; and first and second electrodes, which are positioned apart from one another on the metal chalcogenide layer and comprise metal chalcogenides.

Provided are a metal chalcogenide thin film and a method and device for manufacturing the same. The metal chalcogenide thin film includes a transition metal element and a chalcogen element, and at least one of the transition metal element and the chalcogen element having a composition gradient along the surface of the metal chalcogenide thin film, the composition gradient being an in-plane composition gradient. The metal chalcogenide thin film may be prepared by using a manufacturing method including providing a transition metal precursor and a chalcogen precursor on a substrate by using a confined reaction space in such a manner that at least one of the transition metal precursor and the chalcogen precursor forms a concentration gradient according to a position on the surface of the substrate; and heat-treating the substrate.

Photodiodes configured to convert incident photons in the short-wave infrared (SWIR) to electric current, where the photodiodes have a PbS/PbCl.sub.x core/shell nanocrystal absorber layer. The PbCl.sub.x shell in the PbS/PbCl.sub.x nanocrystals provide native passivation in the (100) crystal facets and enable removal of pre-device processing ligands and ligand exchange on the (111) crystal facets of the PbS/PbCl.sub.x nanocrystals such that the photodiode exhibits reduced current densities under reverse bias and greater infrared photoresponse, providing improved device performance as compared to photodiodes having absorber layers formed from PbS core nanocrystals alone.

The present disclosure is directed to methods for producing a photovoltaic junction that can include coating a bare junction with a composition. In one embodiment, the composition includes a plurality of quantum dots to create a film; exposing the film to a ligand to create a first layer; coating the first layer with the composition to form a film on the first layer; and exposing the film on the first layer to the ligand to create a second layer.

The present disclosure is directed to photovoltaic junctions and methods for producing the same. Embodiments of the disclosure may be incorporated in various devices for applications such as solar cells and light detectors and may demonstrate advantages compared to standard materials used for photovoltaic junctions such as silica. An example embodiment of the disclosure includes a photovoltaic junction, the junction including a light absorbing material, an electron acceptor for shuttling electrons, and a metallic contact. In general, embodiments of the disclosure as disclosed herein include photovoltaic junctions which provide absorption across one or more wavelengths in the range from about 200 nm to about 1000 nm, or from near IR (NIR) to ultra-violet (UV). Generally, these embodiments include a multi-layered light absorbing material that can be formed from quantum dots that are successively deposited on the surface of an electron acceptor (e.g., a semiconductor).

The present invention relates to a photoelectric film and a fabrication method thereof, and in particular, to a layered polycrystalline lead selenide (PbSe) film and a fabrication method thereof. The fabrication method mainly includes: (1) fabricating a dense PbSe layer on a substrate through chemical bath deposition (CBD); (2) fabricating a loose plumbonacrite (Pb.sub.10O(OH).sub.6(CO.sub.3).sub.6) layer on the dense PbSe layer through CBD; (3) placing a sample with the dense PbSe layer and the Pb.sub.10O(OH).sub.6(CO.sub.3).sub.6 layer in a selenium ion-containing solution to allow an ion exchange reaction to finally form the layered polycrystalline PbSe film. The fabrication method has the advantages of simple process, low cost, and high controllability. The PbSe film fabricated by the method is composed of a lower dense polycrystalline cubic PbSe layer and an upper loose polycrystalline cubic PbSe layer, which can be widely used in the fabrication of components in the field of photoelectric conversion or thermoelectric conversion, such as infrared (IR) sensors, solar cells, laser emitters, and thermoelectric converters.

Photovoltaic devices, and methods of fabricating photovoltaic devices. The photovoltaic devices may include a first electrode, at least one quantum dot layer, at least one semiconductor layer, and a second electrode. The first electrode may include a layer including Cr and one or more silver contacts.

Tandem solar cell configurations are provided where at least one of the cells is a metal chalcogenide cell. A four-terminal tandem solar cell configuration has two electrically independent solar cells stacked on each other. A two-terminal solar cell configuration has two electrically coupled solar cells (same current through both cells) stacked on each other. Carrier selective contacts can be used to make contact to the metal chalcogenide cell (s) to alleviate the troublesome Fermi level pinning issue. Carrier-selective contacts can also remove the need to provide doping of the metal chalcogenide. Doping of the metal chalcogenide can be provided by charge transfer. These two ideas can be practiced independently or together in any combination.

An electric field drives nanocrystals dispersed in solvents to assemble into ordered three-dimensional superlattices. A first electrode and a second electrode 214 are in the vessel. The electrodes face each other. A fluid containing charged nanocrystals fills the vessel between the electrodes. The electrodes are connected to a voltage supply which produces an electrical field between the electrodes. The nanocrystals will migrate toward one of the electrodes and accumulate on the electrode producing ordered nanocrystal accumulation that will provide a superlattice thin film, isolated superlattice islands, or coalesced superlattice islands.