Properties of precisely compensated semiconductors

Properties of precisely compensated semiconductors were studied; a phenomenon consisting of a drastic increase in resistivity by several orders of magnitude as the concentration of deep-level impurities increased was observed. It is shown that an anomalous increase in the lifetime of charge carriers, in photoconductivity, and in dark resistivity are related effects. It is demonstrated that, in this case, the semiconductor becomes sensitive to variations in temperature and in the intensity of illumination in the range of interband and impurity absorption; however, these effects are inertial. The highest value of the carriers' lifetime is limited by the band-to-band Auger recombination, for which an empirical expression is suggested. The origin of the above effects is examined and explained in the context of the Shockley-Read-Hall theory of recombination by the example of silicon doped with indium. It is shown that the degree of compensation of a semiconductor can be determined from the temperature dependence of the equilibrium charge-carrier concentration.