Title :
Density of localized state of free carriers in amorphous As2Se3 and As2S3 films
Author_Institution :
Center of Optoelectronics of IFA, Acad. of Sci. of Moldova, Moldova
Abstract :
Photosensitive donor- and acceptor-like centers of 1.05 eV and 0.76 eV energies from the valence band were revealed by photoconductivity measurements. These energies are constant and independent of light intensity in range 1.5×109-1.5×1015 quanta/(cm2·s) and of energy of quanta (> 1.50 eV). Wide quasicontinuous energetic distribution of trap centers state density (N(E)) with maximums at 0.62, 0.87 and 1.05 eV for As2Se3 and at 0.74, 0.92, 0.99, 1.21 eV for As2S3 were found by relaxation measurements of positive and negative charge. N(E) increases in the energy range 0.90-1.05eV as was revealed considering low frequency-capacity dependency in the barrier structure of Al-As2Se3.
Keywords :
amorphous semiconductors; arsenic compounds; electron density; electronic density of states; impurity states; photoconductivity; semiconductor thin films; 0.90 to 1.05 eV; Al-As2Se3; As2S3; As2Se3; amorphous As2S3 film; amorphous As2Se3 film; free carriers; localized state density; photoconductivity; photosensitive acceptor-like centers; photosensitive donor-like centers; relaxation measurements; trap centers state density; valence band; Amorphous materials; Charge measurement; Current measurement; Electrodes; Energy measurement; Frequency; Glass; Optical films; Photoconductivity; Spectroscopy;
Conference_Titel :
Semiconductor Conference, 2002. CAS 2002 Proceedings. International
Print_ISBN :
0-7803-7440-1
DOI :
10.1109/SMICND.2002.1105883
