Конденсированные среды и межфазные границы (Sep 2017)
OPTICAL PROPERTIES OF MULTILAYER STRUCTURES ON THE BASIS OF SOLID SOLUTIONS OF THE SYSTEM CdS–ZnS, OBTAINED BY THE METHOD OF PYROLYSIS OF AEROSOL
Abstract
Multilayer fi lm structures based on solid solutions of the CdS–ZnS system with variable thickness concentrations of cadmium and zinc were obtained by the pyrolysis of aerosol solutions of thiocarbamide coordination compounds. Their transmission spectra, the photoluminescence spectra, and the temperature dependence of the photocurrent are studied. It is shown that the photocurrent at the wavelength of the exciting light (380 nm) is not monotonically dependent on the temperature, which is associated with the competition of carrier excitation and recombination processes The purpose of this work is to study the crystal structure and properties of multilayer structures synthesized by pyrolysis of aerosol on the basis of solid solutions of the CdS–ZnS system with successive changes in the ratios of the atomic fractions of cadmium and zinc ions It is established that the highest photoluminescence intensity is observed for layers precipitated from TCS [M (N2H4CS) 2CI2]. For all the samples, the luminescence bands broadened. The results of X-ray phase analysis showed that all the layers deposited in the multilayer structure have a wurtzite modifi cation, are polycrystalline, and have a pronounced crystallization direction. The multilayer structures synthesized from [M(N2H4CS)2Br2] have a steady-state current value comparable to the values for individual CdS synthesized under similar conditions. Optical studies have shown that the transmission spectra do not refl ect the intrinsic absorption edge for each deposited layer. The value of the bandgap width for CdS → ZnS samples is slightly increased when compared with individual CdS. Multilayer ZnS → CdS samples synthesized from chloride coordination compounds have a greater optical width compared to samples from bromide TCS.
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