Single-step Electrochemical Deposition of CZTS Thin Films with Enhanced Photoactivity

Haribhau Borate,1

Ajinkya Bhorde,1

Ashish Waghmare,1

Shruthi Nair,1

Subhash Pandharkar,1

Ashvini Punde,1

Pratibha Shinde,1

Priti Vairale,1

Vijaya Jadkar,1

Ravindra Waykar,1

Sachin Rondiya,1

Yogesh Hase,1

Rahul Aher,1

Nilesh Patil,1

Mohit Prasad2 

Sandesh Jadkar2*Email

1School of Energy Studies, Savitribai Phule Pune University, Pune 411 007 (India)

2Department of Physics, Savitribai Phule Pune University, Pune 411 007 (India)

Abstract

The CZTS thin films have been deposited on Mo coated corning glass substrate via single-step electrodeposition technique followed by post-annealing treatment at 550˚C for 10 min in Ar-H2S atmosphere. The deposition potential effects on structural, optical, morphological, compositional, and photoelectrochemical (PEC) properties have been investigated through various tools such as x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), energy dispersive x-ray spectroscopy (EDS), UV-Visible spectroscopy, Raman spectroscopy, etc. XRD patterns, XPS, and Raman spectra confirm the formation of CZTS films with no trace of impurities and appreciable crystallinity. EDS analysis shows that high-quality CZTS films with Cu-poor and Zn-rich composition can be synthesized by varying deposition potential from -0.85 to -1.05 V. Formation of interconnected grains with an increase in grain size has been observed from FE-SEM analysis. The bandgap of films was found in the range 1.46-1.57 eV when the deposition potential was varied from -0.85 V to -1.15 V. Photoresponse characteristics show that photocurrent in CZTS films is due to cathodic surface reaction and the photoconductivity is of p-type. The photoelectrochemical impedance spectroscopy (PEIS) analysis showed CZTS film deposited at potential -1.15 V has the highest photocurrent activity. Based on the obtained results in the present study, one can infer that electrodeposited CZTS films can be a potential candidate for optoelectronic applications.

Single-step Electrochemical Deposition of CZTS Thin Films with Enhanced Photoactivity