Optoelectronic properties of undoped and Al, B and Ga-doped In2S3 thin films grown by CBD on flexible PET/ITO substrates

Undoped and Al, B and Ga-doped In2S3 thin films were deposited on flexible PET/ITO substrates using chemical bath deposition by varying the deposition temperatures (60, 70, 80 and 90 degrees C) and growth times (120, 150 and 180 min). Citric acid was used as complexing agent along with indium trichloride and thioacetamide as indium and sulfur sources, respectively. The structural, optical and electrical properties of In2S3 thin films were analyzed by Raman spectroscopy, UV-Vis transmittance spectroscopy and Hall Effect measurement. Structural analysis indicated the tetragonal phase of In2S3 films. The optical characterization showed a maximum transmittance of 80% in the visible region. The band gap energy of In2S3 thin films was tuned from 2.06 to 2.94 eV with respect to doping elements and experimental parameters. The electrical characterization showed n-type conductivity for both undoped and doped In2S3 thin films along with the resistivity values between 1 x 10(-2) and 1 x 10(5) Omega cm.