Indium induced band gap tailoring in AgGa(1-x)In(x)S(2) chalcopyrite structure for visible light photocatalysis

Indium was substituted at gallium site in chalcopyrite AgGaS(2) structure by using a simple solid solution method. The spectroscopic analysis using extended x-ray absorption fine structure and x-ray photoelectron spectroscopy confirmed the indium substitution in AgGaS(2) lattice. The band gap energy of AgGa(1-x)In(x)S(2) (x=0-1) estimated from the onset of absorption edge was found to be reduced from 2.67 eV (x=0) to 1.9 eV (x=1) by indium substitution. The theoretical and experimental studies showed that the indium s orbitals in AgGa(1-x)In(x)S(2) tailored the band gap energy, thereby modified the photocatalytic activity of the AgGa(1-x)In(x)S(2).