Electric Field-effect-assisted Persistent Photoconductivity In CZTS

Copper zinc tin sulfide (CZTS) thin film was deposited by co-sputtering metal targets and post-deposition sulfurization in H2S. Temperature-dependent electrical conductivity and photoconductivity effects in CZTS are studied. The low temperature electrical conductivity measurement shows acceptor level energy value as 36.85 meV. A large decay time of 108 s at 300K, 99 s at 200K and 94 s at 100K after switching off the light source was observed. The decay behavior of this persistent photoconductivity (PPC) in CZTS follows the double exponential function. The results show that defects are responsible for the observed PPC in CZTS. The combined measurements of low temperature electrical conductivity and photoconductivity give account of the defect level. Control of these defects can improve the quality of material and thus the resulting device.