摘要
Asymmetric InGaN/GaN multiple-quantum well（MQW） light-emitting diodes were fabricated to expose the luminescence distribution and explore the hole transport.Under electrical injection,the sample with a wNQW active region in which the first QW nearest the p-side（QW1） is wider than the subsequent QWs shows a single long-wavelength light-emission peak arising from QW1.The inverse nWQW sample with a narrow QW1 shows one short-wavelength peak and one long-wavelength peak emitted separately from QW1 and the subsequent QWs.Increasing the barrier thickness between QW1 and the second QW（QWB1） in the nWQW structure,the long-wavelength peak is suppressed and the total light-emission intensity decreases.It was concluded that the nWQW and thin-QWB1 structure can improve the hole transport,and hence enhance the light-emission from the subsequent QWs and increase the internal quantum efficiency.
Asymmetric InGaN/GaN multiple-quantum well（MQW） light-emitting diodes were fabricated to expose the luminescence distribution and explore the hole transport.Under electrical injection,the sample with a wNQW active region in which the first QW nearest the p-side（QW1） is wider than the subsequent QWs shows a single long-wavelength light-emission peak arising from QW1.The inverse nWQW sample with a narrow QW1 shows one short-wavelength peak and one long-wavelength peak emitted separately from QW1 and the subsequent QWs.Increasing the barrier thickness between QW1 and the second QW（QWB1） in the nWQW structure,the long-wavelength peak is suppressed and the total light-emission intensity decreases.It was concluded that the nWQW and thin-QWB1 structure can improve the hole transport,and hence enhance the light-emission from the subsequent QWs and increase the internal quantum efficiency.
基金
supported by the National High Technology Research and Development Program of China(No.2006AA03A122)
the Knowledge Innovation Program of the Chinese Academy of Sciences(No.ISCAS2009T02)
