Article ID Journal Published Year Pages File Type
1550408 Solar Energy 2013 8 Pages PDF
Abstract

An effective synthesis strategy is employed to fabricate Cu2ZnSnS4 (CZTS) thin films using radio frequency (rf) magnetron sputtering technique on soda lime glass substrates. The as-grown films are annealed at different temperatures ranging between 350 and 550 °C, and their chemical compositions and structural properties are investigated. The as-grown films have poor Cu/(Zn + Sn) ratios ranging between 0.39 and 0.44 and S/(Cu + Zn + Sn) ratios ranging between 0.97 and 1.21. The Cu/(Zn + Sn) ratio is improved by growing a thin additional Cu-capping layer on the as-grown film followed by annealing. An improved Cu/(Zn + Sn) ratio of ∼0.71 is obtained and the S/(Cu + Zn + Sn) ratio is slightly reduced to ∼0.85. The formation of a kesterite type CZTS is confirmed using X-ray diffraction and Raman spectroscopy measurements. Absorption measurements and band-gap energy determination of the CZTS films are carried out in order to confirm applicability to solar cells.

► Precursor CZTS films are non-stoichiometric with binary sulfide phases. ► Cu-capping (140 nm) on precursor CZTS provides near stoichiometric films. ► Raman spectroscopy reveals the formation of CZTS phase after Cu-capping. ► Cu-capped CZTS samples show an improved Cu/(Zn + Sn) ratio of ∼0.71.

Related Topics
Physical Sciences and Engineering Energy Renewable Energy, Sustainability and the Environment
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