Achieving homogeneity of InGaN/GaN quantum well by well/barrier interface treatment.

• A new method is proposed during the growth of InGaN/InGaN multiple quantum well. • This method promotes the luminescence and material homogeneity of InGaN alloy. • The influence of different pretreatment duration is investigated. • This method works by partially releasing the strain in the InGaN well layer. A new pretreatment method is adopted during the metal-organic chemical vapor deposition (MOCVD) epitaxial growth of InGaN/(In) GaN multiple quantum well (MQW), in which when the growth of under barrier of each QW is finished, i. e. before the growth of each well layer, the gallium precursor flow is switched off while indium and nitrogen precursor flows are kept on for an extra period of time. The structural and luminescence properties of samples with different pretreatment duration are investigated by high resolution X-ray diffraction, electroluminescence, temperature dependent photoluminescence and micro-photoluminescence. The results show that a better homogeneity of quantum wells can be achieved by this preprocess. This method operates mainly due to partially releasing the deformation energy and thus attenuating the composition pulling effect in InGaN well layer growth. [ABSTRACT FROM AUTHOR]