Visualizing light-to-electricity conversion process in InGaN/GaN multi-quantum wells with a p–n junction<xref rid="cpb_27_9_097104_fn1" ref-type="fn">*</xref><fn id="cpb_27_9_097104_fn1"><label>*</label><p>Project supported by the National Key Research and Development Program of China (Grant Nos. 2016YFB0400302 and 2016YFB0400603), the National Natural Science Foundation of China (Grant Nos. 11574362, 61210014, and 11374340), and the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission, China (Grant No. Z151100003515001).</p></fn>

Visualizing light-to-electricity conversion process in InGaN/GaN multi-quantum wells with a p–n junction**

Project supported by the National Key Research and Development Program of China (Grant Nos. 2016YFB0400302 and 2016YFB0400603), the National Natural Science Foundation of China (Grant Nos. 11574362, 61210014, and 11374340), and the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission, China (Grant No. Z151100003515001).

Li Yangfeng^{1, 2}, Jiang Yang^{1, 2}, Die Junhui^{1, 2}, Wang Caiwei^{1, 2}, Yan Shen^{1, 2}, Wu Haiyan^{1, 2}, Ma Ziguang^{1, 2}, Wang Lu^{1, 2}, Jia Haiqiang^{1, 2}, Wang Wenxin^{1, 2}, Chen Hong^{1, 2, ‡}

(color online) (a) PL peak energy and full-width at half-maximum (FWHM) as a function of the temperature. The PL peak energy as a function of temperature exhibits an S-shape curve, which indicates the localized states in the quantum wells.^[27,28] The fitted curve obtained from the band-tail model is plotted with a solid line (red) with the fitted σ of 11.62 meV. The U-shaped FWHM curve is also related to the redistribution of carriers in the localized states.^[27] (b) The PLE and PL spectra. The PL emission peak locates at ∼ 2.70 eV for incident photons with the energy at 2.88 eV. Curves A–D represent the PLE spectra with detection energy at 2.76 eV, 2.73 eV, 2.70 eV, 2.68 eV, respectively. The dotted lines indicate the fitted curves of the PLE spectra with a Sigmoidal function,^[29] which calculates a bandgap energy of about 2.95 eV.