Hg_(3-3x)In_2xTe₃: A novel semiconductor material for near infrared photovoltaic detectors

A new photoelectronic semiconductor crystal, mercury indium telluride (MIT), with dimensions of 15mm in diameter and 175mm in length has been successfully grown by using the vertical Bridgman method (VB) at the optimized growth conditions. The crystal was determined through the power X-ray diffraction to be defect zinc-blende structure with the space group F4̄3m. The transmittance spectra from 2.5 to 25μm shows high middle and far-infrared transmittance of 50-55%, which decreases gradually with the increase of wavenumber due to the lattice absorption and free carriers absorption. Hall measurements at room temperature show that the resistivity, carrier density and mobility of the MIT crystal are 4.79×10² Ωcm, 2.83×10¹³ cm^-3 and 4.60×10² cm ²V^-1s^-1, respectively. The reduction of carrier mobility and the increase of the resistivity are related to the adding of In₂Te₃ into HgTe, which changes the energy band structure of the crystal.