CIGS and perovskite solar cells-an overview

Thin-film solar cells based on copper indium gallium selenide (CIGS) and perovskites continue to enhance their market share as promising energy conversion devices for indoor and outdoor applications. CIGS has been known for its high absorption coefficient, tunable bandgap and flexibility. Nevertheless, the use of toxic, regulated elements (cadmium) and reliance on rare elements create a huge barrier in the efforts to enhance the commercial market of CIGS. Perovskite solar cells have attracted increasing scientific and technological interest because of their high efficiency. This is due to their ability to fulfil the multiple roles of light-absorption, charge separation and transport of holes and electrons in materials. Furthermore, they contain low amounts of rare earth materials. However, this technology is still limited by the stability, scale-up and composition of materials. CIGS-perovskite tandem solar cells continue to demonstrate very high efficiencies over 24%. In this study, an overview of the recent developments in material specifications, deposition techniques and device architecture of CIGS and perovskite solar cells is presented.