Abstract: An optoelectronic semiconductor device includes an absorber layer made of a direct bandgap semiconductor and having only one type of doping. An emitter layer is located closer than the absorber layer to a back side of the device, the emitter layer made of a different material than the absorber layer and having a higher bandgap than the absorber layer. A heterojunction is formed between the emitter layer and the absorber layer, and a p-n junction is formed between the emitter layer and the absorber layer at a location offset from the heterojunction. The p-n junction causes a voltage to be generated in the device in response to the device being exposed to light at a front side of the device. The device also includes an n-metal contact disposed on a front side of the device and a p-metal contact disposed on the back side of the device.

Abstract: Embodiments of the invention generally relate to photovoltaic devices and more specifically, to the metallic contacts disposed on photovoltaic devices, such as photovoltaic cells, and to the fabrication processes for forming such metallic contacts. The metallic contacts contain a palladium germanium alloy formed at low temperatures during an anneal process. In some embodiments, the photovoltaic cell may be heated to a temperature within a range from about 20° C. to about 275° C. during the anneal process, for example, at about 150° C. for about 30 minutes. In other embodiments, the photovoltaic cell may be heated to a temperature within a range from about 150° C. to about 275° C. for a time period of at least about 0.5 minutes during the anneal process.

Abstract: Methods and apparatus are provided for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells. In one embodiment of a photovoltaic (PV) device, the PV device generally includes an n-doped layer and a p+-doped layer adjacent to the n-doped layer to form a p-n layer such that electric energy is created when electromagnetic radiation is absorbed by the p-n layer. The n-doped layer and the p+-doped layer may compose an absorber layer having a thickness less than 500 nm. Such a thin absorber layer may allow for greater efficiency and flexibility in PV devices when compared to conventional solar cells.