Conductivity and hall effect in vitreous As2(Se, Te)3

Conductivity and Hall effect measurements are reported on a series of the chalcogenide glasses As2Se3-xAs2Te3 with x = 0.5, 1, 1.5, 2, 2.5 and 3 in the temperature range from -10 to 100°C. The Hall effect measurements were extended to samples with low conductivity down to 5 × 10-8 Ω-1 cm-1. The measuments were performed with a dc apparatus. Both conductivity and Hall coefficient vary exponentially with temperature, but the conductivity lines are somewhat steeper than the Hall coefficient lines. Apparent values of the energy gap were derived from conductivity and Hall effect measurements, the latter being about 10 per cent smaller. The energy gap decreases with increasing tellurium content. the values derived from Hall effect measurements are 1.17 and 0.87 eV for x = 0.5 and 3 respectively. The sign of the Hall coefficient, in all the alloys investigated, showed n-type conductivity which is in apparent contradiction with the sign of the thermoelectric power which indicates p-type conductivity. The Hall mobility increases slightly with the tellerium content. The calculated values for x = 0.5 and 3 are 0.03 and 0.05 cm2 V-1 sec-1 respectively. The Hall mobility shows a slight exponential increase with temperature. The calculated values of the activation energy of the mobility are about 0.05 eV. © 1971

Hall effect in CdGexAs2 glasses

Conductivity and Hall effect measurements have been made on a series of CdGexAs2 glasses with x varying from 0·1 to 0·8 and in the temperature range 300-600 K. The Hall mobility at room temperature exhibits a large variation with the germanium content, having a maximum of 0·28 cm2/V sec at x = 0·7, and a minimum of 0 012 cm2/V sec at x = 0·33. The temperature dependence of the Hall mobility also shows a significant change with increasing x. For low concentrations, up to x = 0·33, the Hall mobility increases slightly with temperature. For x>0·5 it is nearly constant up to 400 K, at which temperature it starts to decrease sharply and appears to approach zero at about 570 K. In the case of CdGe0.8As2, for which it was possible to obtain measurements above 570 K, the Hall mobility starts to increase again above this temperature. The sign of the Hall coefficient was negative for all glasses examined at temperatures below 570 K. However, for CdGe0.8As2 the Hall coefficient, while negative up to 570 K, changes sign at this temperature and becomes positive. © 1977, Taylor & Francis Group, LLC. All rights reserved

Electrical properties of vitreous As2(Se,Te)3 before and after annealing

Detailed measurements of the electrical conductivity versus temperature were performed on vitreous As2(Se,Te)3 alloys before and after annealing at 100°C. The ln σ versus 1/T plots showed a slight departure from linearity with the slope decreasing continuously with decreasing temperature. Hall effect measurements also showed a non linear dependence of the ln RH on 1/T, where RH the Hall coefficient. All the alloys examined showed annealing effects which result in a decrease of the electrical conductivity and a small increase of the activation energy. It was concluded that vitreous semiconductors obtained by quenching from the melt show annealing effects similar to those found in amorphous layers prepared by evaporation on a cold substrate, though in the latter case the effects are more pronounced. © 1972