Over 8% efficient ultrathin kesterite Cu2ZnSnS4 (CZTS) solar cells have been developed by interface reaction route controlling and self-organized nanopattern at the back contact. An ultrathin dielectric Al2O3 intermediate layer is inserted into the Mo/CZTS interface to inhibit the detrimental interfacial reaction between CZTS and Mo, and then turns into a self-organized nanopatterning with opening for electrical contact. The typical issues of phase segregation and voids at the back contact region therefore can be addressed, which reduces back contact recombination and improves the device performance. A 7.6% efficiency world record for 1 cm2 CZTS solar cells also has been achieved by this interface modification.
- Fangyang Liu
- Jialiang Huang
- Xiaojing Hao
