Characteristics of structure formation in zinc and cadmium chalcogenide films deposited on nonorienting substrates
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URFACE AND THIN FILMS
Characteristics of Structure Formation in Zinc and Cadmium Chalcogenide Films Deposited on Nonorienting Substrates A. S. Opanasyuka, D. I. Kurbatova, V. V. Kosyaka, S. I. Kshniakinaa, and S. N. Danilchenkob a
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Sumy State University, RimskyKorsakov str. 2, UA40007 Sumy, Ukraine Applied Physics Institute, National Academy of Sciences of Ukraine,Petropavlovskaya str.58, UA40030 Sumy, Ukraine email: [email protected], [email protected] December 20, 2010
Abstract—The phase composition, texture quality, size of coherent scattering domains, microstrain level, and concentration of stacking faults in zinc and cadmium chalcogenide (ZnS, ZnSe, ZnTe, CdSe, CdTe) films deposited by closespaced vacuum sublimation method on nonorienting substrates have been investi gated. The analysis was performed by Xray diffraction. The substructural characteristics were determined from the physical broadening of diffraction lines using the Hall method and threefold convolution. The dependence of the structural properties of chalcogenide films on the deposition conditions are characterized. DOI: 10.1134/S1063774512070206
INTRODUCTION Currently much attention has been focused on polycrystalline films of A2B6 compounds, which can be used as basic layers of thinfilm solar converters, pho todetectors, hardXray detectors, sensors, electrolu minescent devices, etc. [1–4]. To use these layers in device structures, one must optimize their optical and electrical characteristics, which, to a great extent, are determined by the specific features of structure forma tion. The main requirements to the structure of the films that can be used as basic layers for various microelec tronic devices are as follows: these layers must be tex tured and singlephase and have compositions similar to stoichiometric, columnar structures, and low con centrations of different types of defects in the crystal lite volume [1, 4, 5]. However, many studies of the structural and electrical properties of chalcogenide films revealed their peculiar features, which are tech nologically difficult to exclude or eliminate. These features include the tendency to deviate from the sto ichiometric composition with precipitation, the coex istence of two polymorphic modifications (sphalerite and wurtzite), lamellar morphology of crystallites, high concentration of twins and stacking faults, high level of macro and microstresses, the tendency to form anomalous growth textures, etc. [6–8]. The pres ence of a large number of structural defects, which play the role of recombination centers and deep traps, deteriorates the optical and electrical characteristics of chalcogenide layers. This limits the range of their application as scintillation and detector materials and basic layers in solar energy converters [5, 8]. The pres ence of metastable phases in chalcogenide films as a result of phase transitions causes the temporal insta
bility of the parameters of devices formed on their basis. Thus, the problem of obtaining A2B6 layers with controlle
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