Photoelectric properties of CdTe:Sn semiinsulating crystals

Abstract Experimental investigations of photoelectric properties of semiinsulating CdTe:Sn crystals are carried out. The samples had high sensibility. In the temperature range 80–295 K and spectral band of 0.5–1.8 μm the spectral dependences of photoconductivity (PC), infrared (IR) PC quenching, lux-ampere characteristics (LAC) were studied. The obtained results could be explained in the network of Rose double-centric model taking into consideration the significant location depth of E v +0.8 eV sensitivity centers. These defects are specified by Sn impurity injection into the CdTe lattice and their ionization determines equilibrium characteristics of the studied crystals. Certain parameters of sensitivity centers are estimated. Double optical transitions take place under PC measurement in the photon energy range 0.8–1.25 eV. In comparison with CdTe:Ge the crystals of CdTe:Sn are of higher resistance, dark and non-equillibrium conductivity in them is of the same type – electronic, photocurrent dependence on photoexcitation is linear in the wide range of illumination changes.