Phase characteristics and optical properties of tetrahedrite Cu₁₂Sb₄S₁₃ and Zn_xCu₁₂Sb₄S₁₃ thin films prepared by AACVD

a. Kimberly Weston¹; b. Richard A. Taylor^{1 1}The University of the West Indies, St Augustine Campus

Email: a. kimberly.weston@my.uwi.edu, b. richard.taylor@sta.uwi.edu

Introduction

Cu-Sb-S is a superb candidate for photovoltaics because it has:

• Excellent, broad variation of intrinsic functional properties
• Structure, composition, and stoichiometry versatility
• Earth abundance, low cost, environmental and benign health effects
• Tunable bandgap

AACVD Synthesis

• Deposition of equimolar quantities of aerosolized Cu & Sb dithiocarbamate precursors dissolved in 20 mL THF onto glass substrates was carried out at 500, 550 and 600 °C for 1 hour @ 130 and 150 sccm.

Structural Characterization

• pXRD, XPS & Raman data confirm cubic structure despite reaction conditions.
• SEM-EDS suggest a correlation of composition of tetrahedrite phase Cu₁₂Sb₄S₁₃ with particle sizes ranging from 0.1 to 4 µm.

Optical Properties

• Undoped TFs absorb in the visible region with indirect band gap of ~2.1 eV.
• Zn²⁺ incorporated films are narrowed with a range between 1.7 – 1.9 eV.

Electrochemical Properties

• TFs deposited on FTO/ITO as working electrodes substrates display reversible redox reactions suggesting good stability.

Conclusions

• AACVD produced tetrahedrite Cu₁₂Sb₄S₁₃ thin films at variable temperature and flow rates to control morphology, composition, optical and electrochemical properties for photovoltaics and catalysis.

References

1. Suehiro, S.; et. al; Inorganic Chemistry 2015, 54 (16), 7840-7845.