The present invention concerns a method for the manufacture of the first layer of a back contact layer for thin-layer solar cells in superstrate configuration. In the prior art, this layer is deposited as a compound, for example as a layer of Sb.sub.2Te.sub.3. In accordance with the invention, however, a tellurium-rich surface layer of the cadmium telluride layer is produced, on which a first material is deposited which is capable of forming an electrically conductive second material with tellurium and of producing the second material by reaction of the first material and tellurium in the surface layer. The second material forms the first layer of the back contact layer.

One embodiment of the present invention can provide a system for fabrication of a photovoltaic structure. The system can include a physical vapor deposition tool configured to sequentially deposit a transparent conductive oxide layer and a metallic layer on an emitter layer formed in a first surface of a Si substrate, without requiring the Si substrate to be removed from the physical vapor deposition tool after depositing the transparent conductive oxide layer. The system can further include an electroplating tool configured to plate a metallic grid on the metallic layer and a thermal annealing tool configured to anneal the transparent conductive oxide layer.

A method of fabricating an Ag(Cu)InGaSe (A(C)IGS) based thin film using SeAg.sub.2Se core-shell nanoparticles, an A(C)IGS based thin film fabricated by the method, and a tandem solar cell having the A(C)IGS thin film are disclosed. More particularly, a method of fabricating a densified Ag(Cu)InGaSe (A(C)IGS) based thin film by non-vacuum coating a substrate with a slurry containing SeAg.sub.2Se core-shell nanoparticles, an A(C)IGS based thin film fabricated by the method, and a tandem solar cell including the A(C)IGS based thin film are disclosed. According to the present invention, an A(C)IGS based thin film including Ag is manufactured by applying SeAg.sub.2Se core-shell nanoparticles in a process of manufacturing a (C)IGS thin film, thereby providing an A(C)IGS based thin film having a wide band gap.

An apparatus, system, and method are disclosed for restoring efficiency of a photovoltaic cell. An illumination module illuminates photovoltaic cells so the cells receive a time integrated irradiance equivalent to at least 5 hours of solar illumination. After illumination, an annealing module anneals the photovoltaic cells at a temperature above 90 degrees Celsius for a minimum of 10 minutes. In one embodiment, the illumination module illuminates the photovoltaic cells for a time integrated irradiance equivalent to at least 20 hours of solar illumination. In another embodiment, the illumination module illuminates the photovoltaic cells for a time integrated irradiance equivalent to at least 16 hours of solar illumination while being heated to at least 50 degrees Celsius. In another embodiment, a solar concentrator irradiates the photovoltaic cells in sunlight for at least 10 hours and increases the irradiance of solar illumination on the cells by a factor of 2 to 5.

An encapsulated integrated photodetector waveguide structures with alignment tolerance and methods of manufacture are disclosed. The method includes forming a waveguide structure bounded by one or more shallow trench isolation (STI) structure(s). The method further includes forming a photodetector fully landed on the waveguide structure.

An optical semiconductor device comprises, on a substrate, a fin of diamond-cubic semiconductor material and, at the base of the fin, a slab of that semiconductor material, in a diamond-hexagonal structure, that extends over the full width of the fin, the slab being configured as an optically active material. This semiconductor material can contain silicon. A method for manufacturing the optical semiconductor device comprises annealing the sidewalls of the fin, thereby inducing a stress gradient along the width of the fin.

Techniques for achieving band gap grading in CZTS/Se absorber materials are provided. In one aspect, a method for creating band gap grading in a CZTS/Se absorber layer includes the steps of: providing a reservoir material containing Si or Ge; forming the CZTS/Se absorber layer on the reservoir material; and annealing the reservoir material and the CZTS/Se absorber layer under conditions sufficient to diffuse Si or Ge atoms from the reservoir material into the CZTS/Se absorber layer with a concentration gradient to create band gap grading in the CZTS/Se absorber layer. A photovoltaic device and method of forming the photovoltaic device are also provided.

The present invention relates to a method of manufacturing a photovoltaic device having an ultra-shallow junction layer. In the method, a crystalline silicon substrate is cleaned and a first doped semiconductor layer with 1.12 eV bandgap and 580 nm of thickness is grown on the crystalline silicon substrate by high density plasma electron cyclotron resonance CVD in a preparation condition of a temperature of the crystalline silicon substrate ranging from 50 C. to 250 C. , about 500W of microwave power, deposition pressure below 50 mTorr, about 20 sccm of argon and hydrogen flow rate, SiH.sub.4 flow rate ranging from 1 sccm to 2 sccm, and 2% boroethane flow rate ranging from about 5 seem to 15 sccm. The photovoltaic device of the present invention has advantages of abrupt homo-junction, ultra-thin high-crystallinity silicon-based thin film, highly-doped concentration, high conductivity and high short-circuit current, thereby having improved efficiency.

Photodiode structures and methods of manufacture are disclosed. The method includes forming a waveguide structure in a dielectric layer. The method further includes forming a Ge material in proximity to the waveguide structure in a back end of the line (BEOL) metal layer. The method further includes crystallizing the Ge material into a crystalline Ge structure by a low temperature annealing process with a metal layer in contact with the Ge material.

A back contact back junction thin-film solar cell is formed on a thin-film semiconductor solar cell. Preferably the thin film semiconductor material comprises crystalline silicon. Base regions, emitter regions, and front surface field regions are formed through ion implantation and annealing processes.