Pseudomorphic InGaAs/GaAs and GaAs/AlGaAs asymmetric triangular quantum wells grown by MBE for optoelectronic device applications

We present the growth and properties of asymmetric triangular wells (ATQWs) involving GaAs/Al sub(0.3)Ga sub(0.7)As and strained In sub(x)Ga sub(1-x)As by molecular beam epitaxy. Compositional grading was approximated using a superlattice technique and varying the thickness of the ternary material in each 'cell'. GaAs/AlGaAs ATQWs exhibit narrow low temperature photoluminescence (PL) linewidths of 2 meV for an 11 period 675 angstrom well width. Sub-meV linewidths are obtained for both InGaAs/GaAs rectangular and asymmetric triangular single QWs, indicative of high quality InGaAs material as well as smooth heterointerfaces.