Fabrication of CuInGaSe2 Thin Film Solar Cells using Low-cost Air-stable Inks.

摘要

CuInGaSe2 (CIGS), a promising thin film solar cell material, has gained lots of attention in decades due to its high energy conversion efficiency and potential lower manufacture cost over conventional Si solar cells. As a cheaper processing method compared to vacuum-based techniques, solution-based deposition has been successfully applied to fabricate electronic devices, such as transistors and solar cells. In my research, CIGS thin film solar cells with energy conversion efficiencies up to 8.01% were successfully fabricated using newly developed air-stable, low-cost inks. The inks consist of commercially available, low-cost compounds and solvents and can be processed using a variety of printing and coating techniques. More importantly, it can synthesize CIGS films free of contamination from copper selenides and amorphous carbon which are common issues for most of solution-based techniques. Besides, high-quality micrometer-sized CIGS films were obtained by using our enhanced selenization approach. Various characterization techniques were employed to qualitatively and quantitatively characterize the semiconductor materials and devices fabricated by this process. The mechanism for the transformation from metal salt precursor films to CIGS absorber thin films and the influence of ink composition and selenium vapour pressure on absorber film quality and photovoltaic device performance were investigated and discussed.