Growth and characterisation of high quality GaInP/AlGaInP quantum wells by solid-source molecular beam epitaxy

Photoluminescence (PL), photoluminescence excitation (PLE) and X-ray diffraction (XRD) data on GaInP/Al(Ga)InP quantum wells (QW´s) grown by solid source molecular beam epitaxy (SSMBE) is presented. The structural and optical properties of QW´s grown with either ternary Al _0.52In_0.48P or quaternary (Al_xGa_1-x)_0.52In_0.48P (x~0.53) barriers is contrasted. Both barrier types offer the prospect of high quality structures as demonstrated by narrow PL and XRD linewidths. The PL of thin QW´s (⩽20 Å) is however considerably degraded for the case of AlInP barriers due to reduced electron confinement compared to quaternary AlGaInP. PL and PLE measurements reveal a large Stokes´ shift for these QW´s, which is clear evidence for a change from type-I to type-II behaviour. This observation, together with calculations based on PLE data for the E1-HH1 ground state energy, gives limits on the range of conduction band offsets that may be used which are consistent with the value ΔE _c=0.67ΔE_g recently reported in the literature