A review on pulsed laser deposited CZTS thin films for solar cell applications

Cu₂ZnSnS₄; commonly abbreviated as CZTS is a promising material for low cost thin film solar cells, because of its suitable band gap energy of around 1.5 eV and large absorption coefficient of over 10⁴cm^-1. All the constituents of this material are abundant in the earth's crust, and they are not toxic making it a smarter choice. Since 1996, after the initial success of the CZTS based solar cell (with its light to electrical conversion efficiency of 0.6%), significant progress in this research area has been achieved, especially in the last five years. Now-a-days, the conversion efficiency of the CZTS thin film solar cell has improved to 12%. Over 600 papers on CZTS have been published since 2001, and the majority of these discuss the preparation of CZTS thin films by different methods. So far, many physical and chemical techniques have been employed for preparing CZTS thin films. Among them, the pulsed laser deposition (PLD) is a versatile deposition method. PLD is a simple, but multipurpose, experimental method that finds use as a means of modeling a very diverse range of materials, and in extensive areas of thin film deposition and multi-layer research. This technique is suitable for depositing high quality films with complex compositions because of its influencing properties such as harmonious transfer of species from the target to substrate, enrichment in crystallinity, clean deposition, and simplicity and flexibility in the engineering design. On the occasion of the 25th anniversary of PLD, this manuscript, reviews the synthesis of CZTS semiconductor thin films fabricated by PLD. This review begins with a description of the PLD system, and then introduces the CZTS and preparation of the CZTS target for PLD deposition. A survey of pulsed laser deposited CZTS thin films and their solar cell performance is discussed in detail. Finally, we present perspectives for further developments of PLD for a CZTS based solar cell absorber layer.