The isotype Al 0.05Ga 0.95As/Al 0.35Ga 0.65As interface of the LPE-grown double heterostructure at elevated temperature

Abstract

The isotype interface of a double heterostructure is studied by measuring the capacitance-voltage characteristic ( C/ V technique). For the LPE-grown Al 0.05Ga 0.95As/Al 0.35Ga 0.65As system it is shown that the effective barrier height of the p-type heteroboundary can be estimated even in the range below 25 meV by recording the C/ V characteristic at lower than room temperature. Experimental evidence is given for the first time that the effective barrier height at the isotope p/ P interface of the NpP-type heterostructure may be raised after treatment at elevated temperature. This reaction at the heteroboundary depends on the mechanical stress additionally introduced by the solder. The gradual increase in light output often observed in AlGaAs double heterostructure diodes during operation at elevated temperature can be well approximated by a step-like function of the operation time and a characteristic delay time. The process is mainly thermally controlled with an activation energy of about 0.53 eV. A correspondence is found between the microscopic process at the p/ P interface and the gradual increase in light output. Therefore, it is suggested that the reaction at the isotype interface of LPE-grown AlGaAs heterojunctions is at least partly the origin of the increase in light output during operation at elevated temperature. Both phenomena are not dependent on the operation current and are more effective at low external compressive stress.