Brush Electrodeposited AgGaSe2 Films and Their Optical Characteristics

AgGaSe2 films were brush electrodeposited on tin oxide coated glass substrates at different substrate temperatures. The films were single phase with a chalcopyrite structure. Optical absorption measurements indicated a band gap in the range of 1.74 eV to 1.94 eV with decreasing substrate temperature. Transmission spectra exhibited interference fringes. Using the envelope method, calculated values of the refractive index at 850 nm decreased from 2.60 to 2.42 with decreasing substrate temperature. Optical data were analyzed by the single-effective oscillator model, and the single oscillator energy as well as the dispersion energy were estimated. The single oscillator energy decreased from 3.90 eV to 3.42 eV with increasing substrate temperature. The dispersion energy increased from 18.56 eV to 19.17 eV with increasing substrate temperature.