Optoelectronic properties of polycrystalline CdInTe films

Close-spaced vapor transport combined with free evaporation was used for th e growth of polycrystalline CdInTe films on glass substrates. The optoelect ronic properties of the films were investigated by absorption at 77 and 300 K, and photoluminescence at 77 K with the indium concentration ranged from 0 to 22 at. %. The band-gap energy was found to vary linearly, and the ban d-gap temperature coefficient increases as the indium concentration increas es, It was found that the ionization energy of indium displaced from the ca tionic sites of the CdTe lattice corresponds to a donor level at E-D>32 meV (E(D)similar or equal to 36 meV) below the conduction-band bottom. This le vel and the acceptor level associated with Cd vacancies stay at the same en ergy distance of their corresponding bands for all the indium concentration s studied. The relation between E-g and the lattice parameter is also shown . (C) 1999 American Vacuum Society. [S0734-2101(99)04706-5].