Impact of sulphurization environment on formation of Cu$_2$ZnSn$S_4$ films using electron beam evaporated stacked metallic precursors

Bulletin of Materials Science

P K KANNAN^1¹ 

[1] Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Kandi, Sangareddy 502285, India^1

关键词: Electron beam evaporation;    ramping rate;    CZTS.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The superiority of copper zinc tin sulphide (Cu$_2$ZnSnS$_4$; CZTS) over the existing absorber layer materials is inevitable owing to its cheap, non-toxic and earth abundant constituents with high absorption coefficient value. In thepresent study, CZTS films are prepared by sulphurizing electron beam deposited precursors of glass/Cu/Zn/Sn/Cu and glass/Cu/Sn/Zn/Cu stacking sequences in two different environments i.e., elemental S powder and 5% H$_2$S $+$ N$_2$ gas at different ramping rates. The effect of sulphurization environment and sulphurization ramping rate on the formation of CZTS is investigated using X-ray diffraction and Raman spectroscopy. The morphology and composition of the films are analysed respectively using field emission gun scanning electron microscopy and energy dispersive X-ray spectroscopy. It is observedthat films prepared in elemental S powder at a low ramping rate exhibit better crystallinity with less impurity phases. The presence of ZnS is observed in all the films, while the presence of SnS is observed in films prepared with H$_2$S gas alone, thus concluding that sulphurization in the presence of elemental S powder at a low ramping rate is highly favourable for CZTS film formation. CZTS films with minor ZnS impurity with a bandgap of 1.48 eV is successfully fabricated by usinga glass/Cu/Zn/Sn/Cu precursor stack.

【 授权许可】

CC BY