Electrical and optical properties of sputter-deposited cadmium sulfide thin films optimized by annealing temperature

• Published in: Materials science in semiconductor processing 2012-04, Vol.15 (2), p.125-130
• Main Authors: Kim, Nam-Hoon, Ryu, Seung-Han, Noh, Hyo-Sup, Lee, Woo-Sun
• Format: Article
• Language: English
• Subjects: Annealing temperature; Applied sciences; Cadmium sulfide (CdS); Compound structure devices; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical and optical characteristics; Electronics; Energy; Exact sciences and technology; Natural energy; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optoelectronic devices; Photovoltaic conversion; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solar cells. Photoelectrochemical cells; Solar energy; Sputtering deposition
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2011.09.001

Cadmium sulfide (CdS) is one of the most widely used materials as a window layer in heterojunction thin film solar cells. Sputtering method for the preparation of CdS thin film was employed for the mass-production of large-area deposited CdS thin films. The electrical and optical properties of sputter-deposited CdS thin films varied with the annealing temperature, which were caused by changes in phase composition, grain size, and stoichiometry of CdS thin films. The improved optical transmittance of 72.25% (at average thickness of 843.93nm) and the optical band gap energy of 2.43eV were obtained at the optimum annealing temperature of 400°C. The resistivity below 103-order Ω cm and carrier concentration above 1016carriers/cm3 are suitable for the requirements of window layers at this optimum annealing temperature.