InGaN/GaN MQWs,InGaN/AlGaN MQWs and InGaN/AlInGaN MQWs are grown on (0001) sapphire substrates by MOCVD. Membrane samples are fabricated by laser lift-off technology. The photoluminescence spectra of membranes show a blue shift of peak positions in InGaN/GaN MQWs,a red shift of peak positions in InGaN/AlGaN MQWs and no shift of peak positions in InGaN/AlInGaN MQWs,from those of samples with substrates. Different changes in Raman scattering spectra and HR-XRD (0002) profile of InGaN/AlInGaN MQWs,from those of InGaN/GaN MQWs and InGaN/AlGaN MQWs,are observed. The fact that the strain changes differently among InGaN MQWs with different barriers is confirmed. The AlInGaN barrier could adjust the residual stress for the least strain-induced electric field in InGaN/AlInGaN quantum wells.
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