ELECTRICAL AND PHOTOELECTRIC PROPERTIES OF HETEROJUNCTIONS MoOx/n-Cd1-xZnxTe

The paper presents the results of studies of the optical and electrical properties of MoOx/n-Cd1-xZnxTe semiconductor heterojunctions made by depositing MoOx films on a pre-polished surface of n-Cd1-xZnxTe plates (5 x 5 x 0.7 mm(3)) in a universal vacuum installation Leybold - Heraeus L560 using reactive magnetron sputtering of a pure Mo target. Such studies are of great importance for the further development of highly efficient devices based on heterojunctions for electronics and optoelectronics. The fabricated MoOx/n-Cd1-xZnxTe heterojunctions have a large potential barrier height at room temperature (f0 = 1.15 eV), which significantly exceeds the analogous parameter for the..Ox/n-CdTe heterojunction (f0 = 0.85 eV). The temperature coefficient of the change in the height of the potential barrier was experimentally determined to be d(phi(0))/dT = -8.7.10(-3) eV K, this parameter is four times greater than the temperature coefficient of change in the height of the potential barrier for MoOx/n-CdTe heterostructures. The greater value of the potential barrier height of the MoOx/n-Cd1-xZnxTe heterojunction is due to the formation of an electric dipole at the heterointerface due to an increase in the concentration of surface states in comparison with MoOx/n-CdTe heterostructures, and this is obviously associated with the presence of zinc atoms in the space charge region and at the metallurgical boundary section of the heteroboundary. In MoOx/n-Cd1-xZnxTe heterojunctions, the dominant mechanisms of current transfer are generation-recombination and tunnelingrecombination with the participation of surface states, tunneling with forward bias, and tunneling with reverse bias. It was found that..Ox/n-Cd1-.Zn.Te heterojunctions, which have the following photoelectric parameters: open circuit voltage Voc = 0.3 V, short circuit current I-sc = 1.2 mA/cm(2), and fill factor FF = 0.33 at an illumination intensity of 80 mW/cm(2) are promising for the manufacture of detectors of various types of radiation. The measured and investigated impedance of the MoOx/n-Cd1-xZnxTe heterojunction at various reverse biases, which made it possible to determine the distribution of the density of surface states and the characteristic time of their charge-exchange, which decrease with increasing reverse bias.