Investigation On The Solution-processed Photovoltaic Cells

The photovoltaic cells(PVs) by solution process have gained much attention due to their simple process, low cost and energy saving etc. It is expected to hold big market share in the future. At present, the main focus in PV study is improving the power conversion efficiency and stability. Also, manufacturing cost and the harmful impact made to the environment need to be considered of.In this article, after introducing the working principle and characterization of PV devices, detail rearches concentrating on solution-processed PV devices have been studied, including CZTS and polymer PV devices.Firstly, the fabrication process for different films of CZTS PV devices has been studied. It is aimed to be done using low temperature solution process without selenization/sulfurization. CZTS nanoparticles are synthesized by hot injection approach using non-toxic solvent polyethylene glycol(PEG) for the first time. Besides, CdS thin films are fabricated by chemical bath deposition. At last, CZTS PV devices are successfully fabricated.Secondly, ZnO films of different morphologies are fabricated using different methods. They can be used as a window layer in CZTS PV devices to improve the efficiency. The factors influencing the morphologies of ZnO films are studied.Thirdly, process of fabricating polymer PV devices has been studied, including the dilution of PEDOT:PSS, the treatment with alcohol, the solvent evaporation time, etc. Based on the above study, new donor material named ZKTM, as well as acceptor material(i.e., nitrogen doped grapheme, N-Graphene) has been successfully applied to PV devices.