Effect of pH value on the micro-structures and optical properties of nano-crystalline CuInS₂ by solvothermal method

Abstract

Copper indium disulfide (CuInS₂) nano-particles were synthesized by solvothermal method at 150 °C using copper (I) chloride, indium (III) chloride, thiourea and ethanol as raw materials, and characterized by X-ray diffraction(XRD), field-emission scanning electron microscope (FESEM), and UV-Vis spectra. The effects of pH value on its micro-structures and optical properties were investigated. The results show that, with the pH value increasing, the particle size of the nano-crystalline CuInS₂ increases, and its band gap becomes narrower under alkaline condition. The band gaps of CuInS₂ nano-particles are from 1.52 eV to 1.93 eV, which makes them promising candidates as absorber materials for photovoltaic applications.

Keywords

solvothermal method / CuInS₂ nano-particles / pH value

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