Temperature dependence of interface recombination and radiative recombination in (Al, Ga)As heterostructures

From measurements of the quantum efficiency of Al0.12Ga0.88As-Al0.47Ga0.53As double heterostructures the effective nonradiative carrier lifetime in the active region and at its interfaces is determined. From the dependence of this lifetime on active layer thickness a value for the interface recombination velocity s is obtained. For a particular sample grown by liquid phase epitaxy s turned out to be 1050 cm/s at 300 K; between 110 and 360 K the interface recombination velocity is proportional to exp(−Ea/kT) with an activation energy Ea of 27 meV. In the analysis the radiative coefficient B is taken to be proportional to T−1.5, as theory predicts when a k-selection rule holds. This behavior of B was verified experimentally with temperature-dependent minority-carrier lifetime measurements.