Abstract:
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.
