Electrical characteristics and deep-level admittance spectroscopies of low-temperature grown GaAs p-i-n structures

The properties of low-temperature grown GaAs are studied via the electrical characterization of p-i-n structures with part of the intrinsic layer grown at 300°C. Comparisons are made between the low-temperature and normally grown samples. The current of the low-temperature sample is about two orders of magnitude higher than that of the normally grown sample in both forward and reverse bias. From temperature-dependent analysis, the leakage current of the low-temperature sample is contributed by the recombination current through defect levels around the midgap, from which a recombination lifetime of 9.4×10^-12 s was obtained. By using admittance spectroscopy we observed a dominant electron level at 0.60 eV with a corresponding capture cross section of 1.0×10^-13 cm² that was not observed in the normally grown sample; thus it is believed to be introduced by the As-rich low-temperature layer.