Lightweight and flexible Cu(In,Ga)Se2 solar minimodules: toward 20% photovoltaic efficiency and beyond
Shogo Ishizuka, Yukiko Kamikawa, Jiro Nishinaga
Abstract
Abstract Lightweight and flexible photovoltaic solar cells and modules are promising technologies that may result in the wide usage of light-to-electricity energy conversion devices. This communication presents the prospects of Cu(In,Ga)Se 2 (CIGS)-based lightweight and flexible photovoltaic devices. The current status of flexible CIGS minimodules with photovoltaic efficiency values greater than 18% and future directions to enhance their efficiency values toward >20% are discussed. The effects of cell separation edges, which are formed through a mechanical, laser, or photolithography scribing process used to fabricate solar cells and modules, on the device performance are also discussed. We found that mechanically scribed CIGS device edges, which are present in conventional solar cells and modules, cause deterioration of device performance. In other words, further improvement is expected with appropriate passivation/termination treatment of the edges or replacing mechanical scribing with a damage-free separation process.