Carrier dynamics of high-efficiency green light emission in graded-indium-content InGaN/GaN quantum wells: An important role of effective carrier transfer
Carrier dynamics of high-efficiency green light emission in graded-indium-content InGaN/GaN quantum wells: An important role of effective carrier transfer
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DOI：
10.1063/1.1637959
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发表时间：
2004-01
影响因子：
4
通讯作者：
Yuanping Sun;Yong‐Hoon Cho;E. Suh;H. J. Lee;R. Choi;Y. Hahn
中科院分区：
文献类型：
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作者：
Yuanping Sun;Yong‐Hoon Cho;E. Suh;H. J. Lee;R. Choi;Y. Hahn
采用光致发光（PL）、光致发光激发和时间分辨PL技术研究了In含量梯度的高效绿光InGaN/GaN多量子威尔斯阱（MQW）的光学性质和载流子动力学。由于In含量梯度的InGaN多量子阱阱中强的相分离，在PL谱中清楚地发现了两个分离的InGaN相关峰。InGaN绿色发射（λ 510 nm）的积分强度随着温度从10 K增加到300 K仅下降约7倍，表明强载流子局域化和高量子效率。通过时间分辨光致发光观察到载流子从低In含量区向高In含量区的强迁移，低In含量区载流子局域化弱，高In含量区载流子局域化强。因此，我们得出结论，从弱到强局域态的有效载流子转移起着重要的作用，以提高亮度和量子效率的绿色发光InGaN多量子阱与梯度In含量。
Optical properties and carrier dynamics of high-efficiency green-light-emitting InGaN/GaN multiple quantum wells (MQWs) with graded-In-content were studied by photoluminescence (PL), PL excitation, and time-resolved PL techniques. Two separated InGaN-related peaks were clearly found in PL spectra due to strong phase separation in the well of the graded-In-content InGaN MQWs. The integrated intensity of the main InGaN green emission (∼510 nm) decreased by only about a factor of 7 with increasing temperature from 10 to 300 K, indicating strong carrier localization and high quantum efficiency. Strong carrier transfer from low-In-content region with weak carrier localization to high-In-content part with strong carrier localization was observed by time-resolved PL. Therefore, we conclude that the effective carrier transfer from weakly to strongly localized states plays an important role to enhance brightness and quantum efficiency in the green-light-emitting InGaN MQWs with graded-In content.