The photovoltage in single crystals of α-MoTe₂

Single crystals of α-MoTe₂ having graphite electrodes applied to a cleavage face show a photovoltage when irradiated with light which is absorbed by the α-MoTe₂ crystal. The spectral distribution of photovoltage (at 290 and 77°K) shows maxima near the α-MoTe₂ absorption bands and the properties of the photovoltage, in crystals 150 and 1 μm thick, suggest that it arises from the thermal dissociation of excitons.

The dark electrical conductivity in crystals 150 and 1 μm thick has been measured over the temperature range 77-290°K and activation energies of conduction obtained.