Optical and electrical properties of vanadium-doped ZnTe crystals grown by the temperature gradient solution method

Vanadium-doped ZnTe (ZnTe:V) crystals 30 mm in diameter and 45 mm in length were grown by the temperature gradient solution growth method. The band gap of as-grown ZnTe:V crystals was estimated to be about 2.22 eV. Infrared spectra exhibit a mean transmittance of 50%-60% in the wavenumber range from 500 cm^-1 to 4000 cm^-1. Compared with the intrinsic ZnTe crystal, the resistivity of ZnTe:V is increased 6-7 orders of magnitude up to 10⁹ Ω·cm and the carrier concentration reduced from 10¹⁴ to 10⁸ cm^-3. Accordingly, the THz detection sensitivity is also enhanced by 20%-30%. The improvements on the optical and electrical properties were attributed to the compensation of Zn vacancies by the vanadium element.