Monolithic tandem chalcopyrite-perovskite photovoltaic devices and techniques for formation thereof are provided. In one aspect, a tandem photovoltaic device is provided. The tandem photovoltaic device includes a substrate; a bottom solar cell on the substrate, the bottom solar cell having a first absorber layer that includes a chalcopyrite material; and a top solar cell monolithically integrated with the bottom solar cell, the top solar cell having a second absorber layer that includes a perovskite material. A monolithic tandem photovoltaic device and method of formation thereof are also provided.

This invention relates to cells and devices for harvesting light. Specifically the cell comprises at least one electrode which comprises graphene or modified graphene and layer of a transition metal dichalcogenide in a vertical heterostructure. The cell may be part of a light harvesting device. The invention also relates to materials and methods for making such cells and devices.

A stacked-layered thin film solar cell. The solar cell has reduced absorber thickness and an improved back contact for Copper Indium Gallium Selenide solar cells. The back contact provides improved reflectance particularly for infrared wavelengths while still maintaining ohmic contact to the semiconductor absorber. This reflectance is achieved by producing a back contact having a highly reflecting metal separated from an absorbing layer with a dielectric layer.

Disclosed herein are a solar cell and a method of manufacturing the same. The solar cell module includes a semiconductor substrate, a first passivation film located on a front surface of the semiconductor substrate, a second passivation film located on a rear surface of the semiconductor substrate, a front electric field region located on the first passivation film on the front surface of the semiconductor substrate and being of a same conductivity-type as that of the semiconductor substrate, an emitter region located on the second passivation film on the rear surface of the semiconductor substrate and being of a conductivity-type opposite that of the semiconductor substrate, first electrodes conductively connected to the front electric field region, and second electrode conductively connected to the emitter region.

Disclosed is a manufacturing method of a solar cell, including forming a photoelectric converter including an amorphous semiconductor layer, forming an electrode connected to the photoelectric converter, and performing a post-treatment by providing light to the photoelectric converter and the electrode.

One embodiment of the invention can provide a system for fabricating a photovoltaic structure. During fabrication, the system can form a sacrificial layer on a first side of a Si substrate; load the Si substrate into a chemical vapor deposition tool, with the sacrificial layer in contact with a wafer carrier; and form a first doped Si layer on a second side of the Si substrate. The system subsequently can remove the sacrificial layer; load the Si substrate into a chemical vapor deposition tool, with the first doped Si layer facing a wafer carrier; and form a second doped Si layer on the first side of the Si substrate.

An energy conversion device comprises at least two thin film photovoltaic cells fabricated separately and joined by wafer bonding. The cells are arranged in a hierarchical stack of decreasing order of their energy bandgap from top to bottom. Each of the thin film cells has a thickness in the range from about 0.5 m to about 10 m. The photovoltaic cell stack is mounted upon a thick substrate composed of a material selected from silicon, glass, quartz, silica, alumina, ceramic, metal, graphite, and plastic. Each of the interfaces between the cells comprises a structure selected from a tunnel junction, a heterojunction, a transparent conducting oxide, and an alloying metal grid; and the top surface and/or the lower surface of the energy conversion device may contain light-trapping means.

A solar cell of the present invention includes a collecting electrode on one main surface of a photoelectric conversion section. The collecting electrode includes first and second electroconductive layers in this order from the photoelectric conversion section side, and an insulating layer between the first and second electroconductive layers, the insulating layer having an opening section formed therein. The first electroconductive layer is covered with the insulating layer, contains a low-melting-point material, and is conductively connected with a part of the second electroconductive layer via the opening section. The surface roughness of the second electroconductive layer is preferably 1.0 m to 10.0 m. The second electroconductive layer is preferably formed by a plating method. In order to conductively connect the first and second electroconductive layers, annealing of the first electroconductive layer by heating is preferably performed prior to forming the second electroconductive layer.

An energy conversion device comprises at least two thin film photovoltaic cells fabricated separately and joined by wafer bonding. The cells are arranged in a hierarchical stack of decreasing order of their energy bandgap from top to bottom. Each of the thin film cells has a thickness in the range from about 0.5 m to about 10 m. The photovoltaic cell stack is mounted upon a thick substrate composed of a material selected from silicon, glass, quartz, silica, alumina, ceramic, metal, graphite, and plastic. Each of the interfaces between the cells comprises a structure selected from a tunnel junction, a heterojunction, a transparent conducting oxide, and an alloying metal grid; and the top surface and/or the lower surface of the energy conversion device may contain light-trapping means.

Methods for fabricating busbar and finger metallization over TCO are disclosed. Rather than using expensive and relatively resistive silver paste, a high conductivity and relatively low cost copper is used. Methods for enabling the use of copper as busbar and fingers over a TCO are disclosed, providing good adhesion while preventing migration of the copper into the TCO. Also, provisions are made for easy soldering contacts to the copper busbars.