Recombination velocity of the Ga0.5In0.5P/GaAs interface

Double heterostructures have been grown with the structure Ga0.5In0.5P/GaAs/Ga0.5In0.5P by metalorganic chemical vapor deposition (MOCVD). These GaAs active layers were grown to thicknesses between 1 and 4 μm in this series of devices. The n-GaAs active layers ranged from undoped (2–5×1014 cm−3) to doped layers in the range 1×1017–5×1017 cm−3. Time resolved photoluminescence (PL) was used to extract the minority carrier lifetimes. The latter can be shown to be a function of bulk lifetime and the interface recombination velocity (S). The GaInP/GaAs (undoped) devices produced a PL lifetimes of 14 μs for a 1 μ active layer thickness. Most of the data for undoped GaAs were fit with S<2 cm/s. The doped devices were fit with values of S less than 200 cm/s. These ultralow recombination velocities should be useful for devices ranging from solar cells to diode lasers.