Reactive sintering of Cu_2ZnSnSe_4 pellets at 600 °C with double sintering aids of Sb_2S_3 and Te

摘要

Reactive sintering of Cu_2ZnSnSe_4 (CZTSe) pellets from its component powders of Cu_2Se, ZnSe, and SnSe_2 under different process conditions had been investigated in order to make densification of CZTSe pellets at high temperature of 600 °C without the problem of severe Se deficiency. Selenide precursor powders were synthesized by solid state reaction. Conventional and planetary ball milling were used to mix the component powders. Different sintering aids had been evaluated. Our best process condition is to have the double sintering aids of Sb_2S_3 and Te together for the densification and grain growth of CZTSe pellets made of the planetary ball-milled powders under the continuous supply of Se vapor from the (SnSe_2 + Se) compensation disc. Both of the double sintering aids and compensation disc contributed most in densification, stoichiometry, and grain growth. To understand the development of the best result during the step-heating sintering process, the interrupted experiments were executed by stopping the experiments at different stages.