Title :
Characterization of functional layers of CdTe crystals subjected different surface processing
Author :
Gnatyuk, Dmytro V. ; Poperenko, Leonid V. ; Yurgelevych, Iryna V. ; Dacenko, Oleksandr I. ; Aoki, Toyohiro
Author_Institution :
Fac. of Phys., Taras Shevchenko Nat. Univ. of Kyiv, Kiev, Ukraine
fDate :
Oct. 27 2013-Nov. 2 2013
Abstract :
The surface functional layers of commercial detector-grade CdTe crystals after commonly used surface treatments as polishing chemical etching in bromine-containing solutions and laser annealing with nanosecond pulses of the second harmonic of YAG:Nd laser are characterized. Effects of etching and irradiation with energy density near the melting threshold on the CdTe surface properties are studied using ellipsometry and photoluminescence and also crystals after storage in air were used. The intrinsic emission band at 1.56 eV and broad defect band peaked at 1.45 eV are found in the PL spectra, excited by a semiconductor laser with wavelength of 405 nm at 80 K. The emission in 1.45 eV was associated with carrier recombination at the defects in the surface region, so called the surface state band.
Keywords :
II-VI semiconductors; cadmium compounds; defect states; etching; laser beam annealing; laser beam effects; melting; photoluminescence; polishing; surface recombination; surface states; CdTe; CdTe surface properties; YAG:Nd laser second harmonic nanosecond pulses; bromine-containing solutions; carrier recombination; defect band; detector-grade CdTe crystals; ellipsometry; energy density; intrinsic emission band; irradiation effects; laser annealing; melting threshold; photoluminescence spectra; polishing chemical etching; semiconductor laser; surface functional layers; surface region; surface state band; surface treatment; temperature 80 K; wavelength 405 nm; Chemical lasers; Chemicals; Crystals; Etching; Surface emitting lasers; Surface morphology;
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2013 IEEE
Conference_Location :
Seoul
Print_ISBN :
978-1-4799-0533-1
DOI :
10.1109/NSSMIC.2013.6829829
