Improved photovoltaic performance of Cu2ZnSn(S,Se)4 solar cells with cation substitution-II

With the rapid development of economy, peoples’ demand for energy has been keep increasing for the last two decades. The fast consume of fossil energy not only threatens the sustainability of current development, but impacts our environment with inevitable pollution. Other than fossil energy, soalr energy is clean and renewable. As a result, solar cells attract lots of attention for their ability to convert solar energy to electricity without producing any pollution. Among numerous absorber materials, Cu2ZnSn(S,Se)4 is considered as one of the most ideal absorber materials for its earth-abundant constituent elements, suitable band gap and high absorption coefficient. As we know, the top efficiency of CZTSSe solar cells has arrived 12.6%, but it’s still a long to go to be industrialized (at least 15%), let alone to catch up with its theoretical efficiency (32.8%). However, precise control of the S/Se ratio is very difficult during the process. Moreover, achieving an appropriate crystal phase and controlled stoichiometry during synthesis is still a big challenge. Furthermore, the formation of non-stoichiometric compositions (secondary phases) are often observed along with the CZTS phase. Thus far, it has been understood that these secondary phases suppress the performance of the device by acting as recombination centers. Based on previous achievements about fabrication of CZTS photovoltaic devices, the aim of this project keeps modifying the formation energy/density of these defects and/or their location in the energy gap of the CZTS absorber by cation substitution. Incorporation of anions in the structure of CZTS may offer better flexibility and control over the stoichiometry and the crystal phase. The achievements can make substantial progress in developing sustainable kesterite-based solar cells providing environmental and manufacturing benefits.

Project ID:PB10911-0078
External Project ID:MOST109-2622-E182-005