Description:
<jats:p>This paper reports measurements on amorphous 3As2Se3·2Sb2Se3 films of electrical conductivity as a function of temperature, applied field, and illumination. The low-field dc conductivity between 230 and 370°K varies exponentially with reciprocal temperature. The steep slope of the data suggests excitation across a mobility gap which has the 0°K value (assuming a symmetrical band model) of 1.64±0.02 eV. Above about 7×104 V/cm, the current increases with the field according to the Poole-Frenkel law I∼exp(βFV1/2), where βF=(1/KBT) ×(q3/πεε0d)1/2. By extrapolating the lnI-vs-V1/2 straight lines at various temperatures to the high-field region, a breakdown field strength of about 2×106 V/cm is found. The trap level, using this field strength, is located at 0.446 eV below the conduction band. The spectral response measured from 0.5 to 0.9 μ suggests an intrinsic-type transport with Eph=1.70 ± 0.02 eV as determined from the wavelength, λ1/2, at which the spectral response reaches half of its maximum value. The results of these measurements, together with those reported in Paper I, are interpreted in terms of a plausible energy-band diagram.</jats:p>