The invention defines an approach and process for fabricating all back contact heterojunction solar cells and is described in a Concept paper submitted to DOE under their ARPA-E solicitation which is included below. Although the Concept paper focuses on crystalline silicon/a-Si device structure the process is valid for other solar cell material/device structures. The invention presents a means of eliminating photolithography in fabricating all back contact heterojunction solar cells using ink jet and laser technologies. Uses/Users: 1) A process for fabricating all back contact heterojunction solar cells particularly using an a-Si/c-Si device structure. 2) Potential use in detector technology.
The primary disadvantage of the high-efficiency back-junction solar cell is its high cost related to complicated processing involving several lithographic patterning steps. The price of the cells is affordable to just a few niche applications. As for all back-contact structures ultimately large-scale implementation relies on a low-cost way of defining isolating and contacting regions of different polarities on the rear surface development of lithography-free processes. This process addresses these issues by making solar cell fabrication more simple reducing manufacturing cost improving performance and eliminating photolithography in fabrication process.