Cu2ZnSnS4 (CZTS) is a promising material for use in solar cells. The distinctive characteristics of this substance include its abundance on earth, low cost, non-toxicity, high absorption coefficient, p-type conductivity, and ideal band gap. CZTS has a stannite (ST) and kesterite (KS) crystal structure. Kesterite has more excellent thermodynamic stability compared to stannite. Consequently, CZTS most frequently occurs in this era. Sputtering, thermal evaporation, pulsed laser deposition, spray pyrolysis, chemical vapour deposition, spin coating, electrodeposition, SILAR, sol-gel, solvothermal, and hydrothermal are among the several processes employed for the production of CZTS thin films. The solvothermal and hydrothermal processes are commonly used to produce high-quality nanocrystals with unique morphology, crystallographic structure, and cost-efficient production.Furthermore, the solvothermal and hydrothermal techniques were employed to produce various categories of photovoltaic devices utilising CZTS, including photoelectrochemical cells, dye-sensitised solar cells, perovskite solar cells, and heterojunction solar cells. In addition, the solvothermal and hydrothermal methods were used to fabricate other types of photovoltaic devices using CZTS, such as photoelectrochemical cells, dye-sensitised solar cells, perovskite solar cells, and heterojunction solar cells. Additionally, it provides a survey on using CZTS in photovoltaic applications, which are produced by hydrothermal and solvothermal techniques. The article also addresses the obstacles encountered in implementing these applications. Lastly, it provides the opportunity to identify remedies for these difficulties.