Stokes shift in semi-polar ( 112¯2) InGaN/GaN multiple quantum wells
Stokes shift in semi-polar ( 112¯2) InGaN/GaN multiple quantum wells
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DOI：
10.1063/1.4940396
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发表时间：
2016-01
影响因子：
4
通讯作者：
Yiwei Zhang;R. Smith;Y. Hou;B. Xu;Y. Gong;J. Bai;Tao Wang
中科院分区：
文献类型：
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作者：
Yiwei Zhang;R. Smith;Y. Hou;B. Xu;Y. Gong;J. Bai;Tao Wang
InGaN/GaN结构的大斯托克斯位移的机制仍在争论中。本文报道了半极性（112 2）InGaN/GaN多量子威尔斯阱（MQW）的斯托克斯位移的系统研究，该MQW具有从绿色（490 nm）到黄色（590 nm）的宽光谱范围，通过光致发光激发和时间分辨PL测量与它们的c面对应物进行比较。半极性样品表现出较低的斯托克斯位移比他们的c-平面对应，虽然他们表现出更强的本地化效应比他们的c-平面对应。在长波长区，半极性多量子阱的斯托克斯位移与发射能量呈线性关系，但与c面多量子阱相比，斯托克斯位移的梯度较小。的时间分辨PL测量证实了显着减少的压电场的半极性样品相比，C-平面的同行。认为压电场激发极化是引起大应变的主要机制。
The mechanism for the large Stokes Shifts of InGaN/GaN structures is under debate. Here, we report a systematic study on the Stokes shift of semi-polar ( 112¯2) InGaN/GaN multiple quantum wells (MQWs) with a wide spectral range from green (490 nm) to yellow (590 nm) by means of both photoluminescence excitation and time resolved PL measurements in comparison with their c-plane counterparts. The semi-polar samples exhibit a lower Stokes shift than their c-plane counterparts, although they show stronger localization effect than their c-plane counterparts. In the long wavelength region, the Stokes shift of the semi-polar MQWs shows a linear relationship with emission energy, but with a smaller gradient compared with their c-plane counterparts. The time-resolved PL measurements confirm a significant reduction in piezoelectric field of the semi-polar samples compared with the c-plane counterparts. It is suggested that the piezoelectric field induced polarization is the major mechanism for causing the large Sto...