ZnSnP 2, an absorber material for solar cells, transitions from an ordered chalcopyrite to a disordered sphalerite structure at high temperatures. We investigate the electronic structure of both phases, combining a screened hybrid density functional with the special quasi-random structure method. We predict a bandgap reduction of 0.95 eV between the ordered and fully disordered materials. Experimental reports are consistent with partial disorder. Tuning of the order parameter would lead to a family of ZnSnP 2 phases with bandgaps ranging from 0.75 eV to 1.70 eV, thus providing graded solar cell absorbers from a single material system.
Bibliographical noteFunding Information:
We acknowledge membership of the UK’s HPC Materials Chemistry Consortium, which is funded by EPSRC Grant EP/F067496, and the Materials Design Network. D.O.S. is grateful to the Ramsay Memorial Trust and University College London for the provision of a Ramsay Fellowship. A.W. acknowledges support from the Royal Society for a University Research Fellowship.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)