Effect of deposition temperature on the growth mechanism of chemically prepared CZTGeS thin films

Abstract

The Cu2ZnSnGeS4 (CZTGeS) thin films were deposited by the spray pyrolysis method at different substrate temperatures without further sulfurization. The influence of various deposition temperatures on the surface morphology, microstructure, optical properties, chemical, and phase composition were investigated. The substitution mechanism of Sn/Ge in the crystal lattice of CZTGeS depending on deposition temperatures was studied. It was shown that a variation in substrate temperature has a strong effect on the surface morphology of the films. The X‐ray diffractometer (XRD), transmission electron microscope (TEM), and Raman spectroscopy (RS) analysis showed that CZTGeS films were polycrystalline with a kesterite‐type single‐phase structure and a preferential orientation of (112). The RS‐mapping analysis showed the distribution of intensities on the surfaces of the films. Optical measurements showed that CZTGeS films are highly absorbing in the visible region, and the optical band gap is shifted from 1.89 to 1.84 eV.

Optimization of sulphurization temperature for the production of single-phase CZTS kesterite layers synthesized by electrodeposition

“…Thin films solar cells based on chalcogenide material Cu(In,Ga)Se 2 achieved a high efficiency beyond 22% [6] while for CZTS solar cells the maximum reported efficiency was 12.6% by non-vacuum deposition method [7] and 11.6% by vacuum method [8]. The low performance of CZTS solar cells is due to the low open-circuit voltage (Voc) [9] and the formation of secondary phases in the CZTS absorber layer. So, one of the challenges in the synthesis of CZTS is how to identify, control and remove these secondary phases in order to reach higher conversion efficiencies.…”