Publikationsdatum:
2014-09-20
Beschreibung:
The order-disorder transition in kesterite Cu 2 ZnSnSe 4 (CZTSe), an interesting material for solar cell, has been investigated by spectrophotometry, photoluminescence (PL), and Raman spectroscopy. Like Cu 2 ZnSnS 4 , CZTSe is prone to disorder by Cu-Zn exchanges depending on temperature. Absorption measurements have been used to monitor the changes in band gap energy ( E g ) of solar cell grade thin films as a function of the annealing temperature. We show that ordering can increase E g by 110 meV as compared to fully disordered material. Kinetics simulations show that E g can be used as an order parameter and the critical temperature for the CZTSe order-disorder transition is 200 ± 20 °C. On the one hand, ordering was found to increase the correlation length of the crystal. But on the other hand, except the change in E g , ordering did not influence the PL signal of the CZTSe.
Print ISSN:
0003-6951
Digitale ISSN:
1077-3118
Thema:
Physik
