The structural and electronic properties of Cu2 ZnSnS 4 and Cu2 ZnSnSe4 are studied using first-principles calculations. We find that the low energy crystal structure obeys the octet rule and is the kesterite (KS) structure. However, the stannite or partially disordered KS structures can also exist in synthesized samples due to the small energy cost. We find that the dependence of the band structure on the (Cu,Zn) cation ordering is weak and predict that the band gap of Cu 2 ZnSnSe4 should be on the order of 1.0 eV and not 1.5 eV as was reported in previous absorption measurements.
Bibliographical noteFunding Information:
The work in Fudan (FU) is partially supported by the National Sciences Foundation of China, the Basic Research Program of MOE and Shanghai, the Special Funds for Major State Basic Research, and Postgraduate Innovation Fund of FU. Computations were performed in the Supercomputer Center of FU and CCS. The work at NREL is funded by the U.S. Department of Energy, under Contract No. DE-AC36-08GO28308.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)