FIR photoconductivity spectra and kinetics in narrow-gap HgCdTe bulk films and HgCdTe based QW

Investigation into far infrared photoconductivity in narrow gap epitaxial bulk Hg_1-xCd_xTe (x<;0.2) films and Hg_1-xCd_xTe/Cd_yHg_1-yTe QW structures grown by molecular beam epitaxy technique is presented. A broad band of photosensitivity in terahertz region is found at 4.2 K - 77 K. Some long-wavelength peculiarities of spectra are discovered and their origins are discussed. Lifetime studies demonstrate the possibility of radiative recombination at high excitation regime. Estimations of ampere-watt sensitivity show that some of the structures are applicable for detecting in very long-wavelength infrared range.