Effect of growth interruption and strain buffer layer on PL performance of AlGaAs／GaAs／InGaAs quantum well for 1065 nm wavelength lasers

Strained InGaAs/GaAs quantum well (QW) was grown by low-pressure metallorganic chemical vapor deposition (MOCVD). Growth interruption and strain buffer layer were introduced to improve the photoluminescence (PL) performance of the InGaAs/GaAs quantum well. Good PL results were obtained under condition of growth an interruption of 10 s combined with a moderate strain buffer layer. Wavelength lasers of 1064 nm using the QW were grown and processed into devices. Broad area lasers (100 μm × 500 μm) show very low threshold current densities (43 A/cm2) and high slop efficiency (0.34 W/A, per facet).     

MOCVD Growth of Doped GaAs/AlGaAs Quantum Heterostructures

The influences of growth techniques of AP-MOCVD GaAs/AlGaAs silicon-doped multi-quantum wells(MQWs), heterostructure bipolar transistors (HBTs), double barrier resonant tunneling diodes(DBRTDs) ontheir structures and performances were studied. Continuously grown MQWs, that is, no growth interruption atthe heterointerfaces, shown blue-shifted, narrower and stronger photoluminescence(PL) compared withinterruptedly grown ones.TEM examination of the interrupted interfaces revealed a bright line correspondingto the compositional fluctuation and impurity adsorption, and indicated noncommutative structures ofAlGaAs/GaAs and GaAs/AlGaAs interfaces. High performance HBTs and DBRTDs were obtained bycontinuously grown method while growth interruption caused performance degradation. It was concluded thatgrowth interruption may cause accumulation of residua1 impurities in the ambient as well as compositionalfluctuation while continuous growth at very low growth rates can overcome such problems.