Optical properties of Cu(In, Ga)Te2 thin films

• Published in: Journal of physics. D, Applied physics Vol. 42; no. 1; pp. 015301 - 015301 (4)
• Main Authors: Yandjah, L, Ayed, H, Amara, A, Benabdeslem, M, Benslim, N, Bechiri, L, Otmani, A, Mahdjoubi, L, Portier, X
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.01.2009; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Other semiconductors; Physics; Tellurides; Annealing; Energy levels; Bound state; Excitation intensity; Photoluminescence; Visible spectra; Polycrystals; Infrared spectra; Flashing; Thin films; Near infrared radiation; Energy gap; Acceptor donor pair; Defect structure
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/42/1/015301

Structural and optical properties of polycrystalline Cu(In, Ga)Te2 thin films were analysed. They were deposited onto glass substrate by the flash evaporation technique and annealed at 450 deg C in an argon atmosphere. Their optical properties in the near-infrared and visible range, 500-3000 nm, were studied to determine the gap. To identify the energy levels associated with various defect structures, photoluminescence (PL) measurements were carried out. The behaviour of the PL spectrum as a function of temperature and excitation intensity in these samples is reported. The PL spectrum of thin films after annealing in an argon atmosphere at 450 deg C showed two peaks ranging from 0.90 to 1.15 eV. The first one, localized at 1.00 eV, was attributed to donor-acceptor pair transition while the second one at 1.05 eV was ascribed to a free-to-bound (F-B) transition.