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Blue In0.2 Ga0.8N multiple quantum wells (MQWs) with Inx Ga1xN (x=0.01 0.04) barriers are grown by metal organic vapour phase epitaxy.The internal quantum efficiencies (IQEs) of these MQWs are studied in a way of temperature-dependent photoluminescence spectra.Furthermore,a 2-channel Arrhenius model is used to analyse the nonradiative recombination centres (NRCs).It is found that by adopting the InGaN barrier beneath the lowest well,it is possible to reduce the strain hence the NRCs in InGaN MQWs.By optimizing the thickness and the indium content of the InGaN barriers,the IQEs of InGaN/InGaN MQWs can be increased by about 2.5 times compared with conventional InGaN/GaN MQWs.On the other hand,the incorporation of indium atoms into the intermediate barriers between adjacent wells does not improve IQE obviously.In addition,the indium content of the intermediate barriers should match with that of the lowest barrier to avoid relaxation.
Blue In0.2 Ga0.8N multiple quantum wells (MQWs) with Inx Ga1xN (x = 0.01 0.04) barriers are grown by metal organic phase evaporation epitaxy.The internal quantum efficiencies (IQEs) of these MQWs are studied in a way of temperature- dependent photoluminescence spectra. Stillrther, a 2-channel Arrhenius model is used to analyze the nonradiative recombination centers (NRCs) .It is found that by adopting the InGaN barrier beneath the lowest well, it is possible to reduce the strain therefore the NRCs in InGaN MQWs.By optimizing the thickness and the indium content of the InGaN barriers, the IQEs of InGaN / InGaN MQWs can be increased by about 2.5 times compared with conventional InGaN / GaN MQWs.On the other hand, the incorporation of indium atoms into the intermediate barriers between adjacent wells does not improve IQE obviously. In addition, the indium content of the intermediate barriers should match with that of the lowest barrier to avoid relaxation.