International Journal of Research in Engineering and Innovation Vol-1, Issue-6 (2017), 143-146 __________________________________________________________________________________________________________________________________ International Journal of Research in Engineering and Innovation (IJREI) journal home page: http://www.ijrei.com ISSN (Online): 2456-6934 _______________________________________________________________________________________ Corresponding author: Ho Soonmin 143 Email Id: soonmin.ho@newinti.edu,.my Synthesis and characterization of ternary Cu 4 SnS 4 Nanocrystalline semiconductor thin films: A review Ho Soonmin Centre for Green Chemistry and Applied Chemistry, INTI International University, Malaysia _______________________________________________________________________________________ Abstract Recently, a significant number of researches have been carried out regarding the synthesis of Cu4SnS4 thin films. This review will try to cover preparation of Cu4SnS4 films by using various deposition methods. The obtained films were investigated using various tools such as scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction and UV-visible spectrophotometer. ©2017 ijrei.com. All rights reserved Keywords: Thin films, Semiconductor, Nanocrystalline, Solar cells _______________________________________________________________________________________ 1. Introduction Binary [1-14] and quaternary [15-19] thin films have attracted much attention in recent years. These films have been developed and characterized by many researchers. Ternary Cu4SnS4 thin films are well known for applications in a wide range of thermoelectric and solar cell devices. Some unique properties such as high thermoelectric, low thermal conductivity and tunable electronic properties make them applicable for the mentioned uses. Cu4SnS4 films have a direct band gap of 1.2 eV, resulting in a high absorption coefficient. Appropriate band gap, high natural abundance [20], non-toxic and low cost [21] of starting materials are the objectives in photovoltaic research and applications. The need for economical energy source has increased interest in the development of solar applications. This paper reports the preparation of Cu4SnS4 thin films by using various deposition techniques. The experimental conditions limiting the behavior of the obtained films were discussed. Studies are focused on structure, surface morphology, optical absorption and composition of these Nano crystalline films. 2. Literature survey Many deposition techniques have been developed for depositing Cu4SnS4 nano crystalline thin films. Generally, these techniques could be divided into two major groups, namely physical or chemical deposition method based on the nature of deposition process. Among them, deposition from aqueous solutions using chemical deposition technique is the most important method due to simple, cheap and easy to scale up. Thermal co-evaporation was used to prepare Cu4SnS4 thin films on glass substrate at a constant substrate temperature of 400°C as reported by Vani and co-workers [22]. The main objective of their works was to investigate the effects of source-substrate distance (10-25 cm) on the chemical and physical properties of films. The energy dispersive X-ray analysis (EDAX) analysis of the deposited films showed that the films are stoichiometric at a source-substrate distance of 20 cm. The strong peaks related to the presence of copper, Sulphur and tin and no other impurity peaks were found in the spectrum within the EDAX detection limit. The scanning electron microscopy (SEM) studies showed needle like grains were distributed on the substrate surface. Further, they observed that as source-substrate distance increases, the grain size decreases. X-ray diffraction (XRD) investigations revealed that the deposited films were Nano crystalline in nature and displayed (311) peak as preferred orientation, indicating orthorhombic structure. Energy band gap of the Cu4SnS4 films was calculated from the observed transmittance data, indicating that varied in the range, 1.25-1.34 eV with the change of source-substrate distance. Simple mechanochemical ball milling process will be employed in order to synthesis Cu4SnS4 (CTS) as described by