The team at SPECIFIC Innovation and Knowledge Centre at Swansea University’s College of Engineering investigated Cu2ZnSn(S,Se)4 (CZTS) which is based on Earth-abundant-elements, has shown great potential as an alternative to conventional Cu(In,Ga)Se2 (CIGS) in solar cells. The power conversion efficiency of CZTS-based solar cells has reached 12.7%, but there is still room for improvement to compete with the 22.3% record of CIGS technologies.