Rapid fabrication and characterization of CuGaS2:Ti intermediate-band material by the solvothermal method

In order to further optimize the solvothermal method for preparing Ti-doped CuGaS2 (CGS2:Ti) film, we have developed a simpler and rapider process of chemical synthesis for 30 min followed by annealing for 30 min. XRD, FESEM, EDAX, XPS, Raman spectra, UV–Vis–NIR absorption spectra and photoelectricity properties have been characterized. As a result, by partially replacing Ga atoms with Ti in the CGS2 chalcopyrite crystal, a narrow partially filled intermediate band (IB) was introduced, and two additional absorption bands were directly observed at 1.61 eV and 0.84 eV spectrum. A photoelectrochemical study of CGS2:Ti confirmed the broad-spectrum solar response produced by the IB effect. The present method is facile, does not need sulfuration process and large energy consumption, avoids the use of toxic substances and vacuum equipment, and may be a promising method for intermediate-band solar cells (IBSC).