L-cystine-assisted synthesis of Cu2ZnGeS4 nanocrystal powder via solvothermal process

•Cu2ZnGeS4 powders were prepared by the l-cystine-assisted solvothermal method.•Cu2ZnGeS4 powders consist of nanocrystal particles.•The Cu2ZnGeS4 powder had a broad absorption band with a band gap of 2.15 eV.

Cu2ZnGeS4 powders were successfully synthesized via a mild solvothermal method using CuCl, ZnCl2, GeCl4, l-cystine, and N, N-dimethylformamide as the precursors to realize the process at 200 °C for 24 h. XRD, FE-SEM, XPS, and TEM were employed to characterize the microstructures and constituents of the as-obtained Cu2ZnGeS4 powders. The results showed that the crystalline phase of the as-obtained powders was Cu2ZnGeS4, and the size of the Cu2ZnGeS4 powders ranged from 100 to 200 nm. UV–vis absorption spectrum showed that the Cu2ZnGeS4 powders exhibited a broad absorption band with a band gap of 2.15 eV in the whole visible range.