CHARACTERIZATION OF RECOMBINATION CENTERS IN N-TYPE HG1-XCDXTE

The defect levels in Hg1-xCdxTe P+N junction photodiodes (x = 0.4) wer e first studied using deep-level transient spectroscopy. Two electron traps, E(1)(0.06) and E(2)(0.15), and two hole traps, H-1(0.075) and H -2(0.29), were obtained, Characteristic parameters-the minority lifeti me of the devices and the dynamic resistance-area product at zero bias -are estimated according to these levels. Results show that these two minority levels may be important in controlling lifetime. We have stud ied the recombination mechanism of the hole trap H-2(0.29) further. It has a large activation energy and satisfies the formula sigma(T) = si gma(x) exp(-E(F)/E(T)). This reflects the fact that its recombination mechanism is multiphonon nonradiative recombination, which is rarely r eported in narrow-bandgap materials.