Abstract
Copper indium gallium diselenide (CIGS), which is cheap and has high efficiency, is one of the potential solar cells. In addition to CIGS absorber layer, the study on buffer layer and interface is also important for photovoltaic application. It means the fabrication of buffer layer much influences junction properties and cell performance. Recently, CIGS solar cell with cadmium sulfur buffer layer fabricated by chemical bath deposition (CBD) has the highest efficiency. Therefore, not only film properties but also interface quality are improved by CBD process. In this thesis, effects of CBD process on CIGS solar cell are focused. It is divided into three parts. In the first part, effects of CBD process on CdS film properties are discussed. Optimum quality of CdS film is obtained by controlling precursor concentration. In the second part, effects of CBD process on interface modification (surface etching and cadmium diffusion) are discussed. Interface could be improved by the enhancement of these modifications. In the final part, by taking two different effects above mentioned into consideration, adequate CdS buffer layer for CIGS solar cell application could be prepared by depositing CdS buffer layer on sputtering CIGS film prepared by quaternary compound target. In this circumstance, nearly 7% efficiency is demonstrated.