The present invention comprises thin film Cu.sub.2S with ultra-large grains or in the best case no grain boundaries (a single crystal thin film). Based on our recent successes in atomic layer epitaxy of other materials we sought and found a suitable substrate (namely GaAs) that induces what appear to be Cu.sub.2S single crystal thin films.

A photovoltaic cell manufacturing method includes depositing a first buffer layer for performing lattice relaxation on a first silicon substrate; depositing a first photoelectric conversion cell on the first buffer layer, the first photoelectric conversion cell being formed with a compound semiconductor including a pn junction, and the first photoelectric conversion cell having a lattice constant that is higher than that of silicon; connecting a support substrate to the first photoelectric conversion cell to form a first layered body; and removing the first buffer layer and the first silicon substrate from the first layered body.

The method of making a gallium antimonide near infrared photodetector is a physical vapor deposition-based method of forming a thin film of gallium antimonide (GaSb) on a mica substrate for use as a photodetector for light in the near infrared range. Following physical vapor deposition (PVD) of the thin film of GaSb on the mica substrate, a pair of spaced apart electrodes is attached to the thin film of GaSb, thus forming the gallium antimonide near infrared photodetector.

The object of the present invention is a photovoltaic cell structure, comprising a p-type semiconductor substrate with a bottom electric contact, upon which a layer comprising ZnO nano structures is made, covered with a Zn Mg O layer and with a transparent conductive layer, preferably ZnO:Al layer, with an electric contact, characterized in that the active layer is a Si/ZnO/ZnMgO junction, the layer of ZnO nano structures of the height of 100 nm up to 2000 nm being covered with the ZnMgO layer from 1 nm to 2000 nm thick, and the method to produce the same.

A method to produce thin film solar cells in superstrate or substrate configuration is an efficient way to minimize the loss due to absorption in CdS layer and to eliminate the CdCl.sub.2 activation treatment step. This is achieved by applying a sacrificial metal-halide layer between the CdS-layer and the CdTe-layer of the solar cells.

A radiation detector for detecting ultraviolet energy having a single crystal UV radiation detector material and an amorphous support layer disposed directly on the single crystal UV radiation detector material with the single crystal UV radiation detector material having a c-axis aligned along a direction of the ultraviolet energy being detected.

A radiation detector for detecting ultraviolet energy having a single crystal UV radiation detector material and an amorphous support layer disposed directly on the single crystal UV radiation detector material with the single crystal UV radiation detector material having a c-axis aligned along a direction of the ultraviolet energy being detected.

A roll-to-roll reactor, which is assembled with an RTP (Rapid Thermal Process) compartment, a cooling compartment, and a series of modular heating sections, is provided. Its length is adjustable by adding or reducing numbers of the modular heating sections according to required reaction time and delivery speed of a continuous flexible workpiece. The reactor contains a reaction oven, assembled with a series of modular thermal control components, included inside a vacuum-tight reaction chamber. The oven temperature can be precisely controlled through combinations of heating elements, thermocouples and cooling tubing. The present reactor can be used for annealing and reaction of various precursor films on flexible substrates under vacuum and in inert or reactive gas ambient at temperatures ranging from room temperature to a thousand of Celsius degrees through a continuous roll-to-roll process.

The present invention presents a process for preparing a quantum dot array comprising at least the steps of: (a) providing a crystalline semiconductor substrate surface; (b) depositing quantum dots on the said substrate surface by a process of successive ionic layer adsorption and reaction (SILAR). The steps can be repeated to build up a quantum dot superlattice structure.

A method of spray deposition for inorganic nanocrystal solar cells comprising subjecting a first solution of CdTe or CdSe nanocrystals to ligand exchange with a small coordinating molecule, diluting the first solution in solvent to form a second solution, applying the second solution to a substrate, drying the substrate, dipping the substrate in a solution in MeOH of a compound that promotes sintering, washing the substrate with iPrOH, drying the substrate with N.sub.2, and heating and forming a film on the substrate. An inorganic nanocrystal solar cell comprising a substrate, a layer of metal, a layer of CdTe, a layer of CdSe, and a layer of transparent conductor. An inorganic nanocrystal solar cell comprising a transparent conductive substrate, a layer of CdSe, a layer of CdTe, and a Au contact.