Abstract：High voltage light emitting diodes (HV-LEDs) have potential advantages on general lighting application for their special features. But as novel power LEDs, their optical, electrical and thermal characteristics still need to be further studied. In this paper, 6 and 9 V GaN-based HV-LEDs were packaged in the same package structure and process conditions. The optical characteristics of two samples were investigated under different temperatures range from 10 to 70 ℃ which were calibrated to junction temperatures using thermal impedance measurement. To ensure the same current density, working current was set to 150 mA for 6 V sample and 100 mA for 9 V sample respectively. Results show that the increasing junction temperature has a great effect on EL spectra of two samples, such as peak wavelength red-shifting, full width at half maximum (FWHM) broadening, luminous efficiency reducing and color rendering index (CRI) increasing. The junction temperature of 9V sample is lower than that of 6 V sample in the same platform temperature and injection power. With temperature increasing, the extended quantitative value of FWHM for 9 V sample is 1.3 nm less than that of 6 V sample, the reduced quantitative value of luminous efficiency is 1.13 lm·W-1 less than that of 6 V sample, while the increased quantitative value of CRI is 0.28 less than that of 6 V sample. Those data suggest that EL spectra of HV-LEDs is less affected by junction temperature than traditional LEDs. It is because HV-LEDs perform better in current spreading and generate less heat. This conclusion has reference value for study, development and applications of GaN-based HV-LEDs. In addition, peak wavelength still has a good linear relationship with junction temperature and it can be a temperature-sensitive parameter when the spectra measurement accuracy is enough.
Key words：High-voltage light emitting diodes (HV-LEDs);EL spectra;Junction temperature;Peak wavelength;Full width at half maximum (FWHM);Luminous efficiency;Color rendering index (CRI)
李松宇，郭伟玲*，孙 捷，陈艳芳，雷 珺 . 结温对高压白光LED光谱特性的影响 [J]. 光谱学与光谱分析, 2017, 37(01): 37-41.
LI Song-yu, GUO Wei-ling*, SUN Jie, CHEN Yan-fang, LEI Jun . Effect of Junction Temperature on EL Spectra of GaN-Based White High Voltage LEDs . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(01): 37-41.
[1] Pimputkar S, Speck J S, DenBaars S P, et al. Nature Photonics, 2009, 3(4): 180. [2] Nakamura S, Pearton S, Fasol G. The Blue Laser Diode. 2nd ed. New York: Springer-Verlag, 2000. [3] Komine T, Nakagawa M. IEEE Transactions on Consumer Electronics, 2004, 50(1): 100. [4] CAO Dong-xing, GUO Zhi-you, LIANG Fu-bo, et al(曹东兴，郭志友，梁伏波，等). Acta Physica Sinica(物理学报), 2012, 61(13): 511. [5] Zhan Teng, Zhang Yang, Ma Jun, et al. IEEE Photonics Technology Letters, 2013, 25(9): 844. [6] Wang C H, Lin D W, Lee C Y, et al. IEEE Electron Device Letters, 2011, 32(8): 1098. [7] Tao Y B, Wang S Y, Chen Z Z, et al. Phys. Status Solidi C, 2012, 9(3~4): 616. [8] Yoshihiro Ohno. Optical Engineering, 2005, 44(11): 111302. [9] BAI Jun-xue, GUO Wei-ling, YU Xin, et al(白俊雪，郭伟玲，俞 鑫，等). Chinese Journal of Luminescence(发光学报), 2014, 35(1): 101. [10] Wu J, Walukiewicz W, Yu K M, et al. Applied Physics Letters, 2002, 80(25): 4741. [11] Wang Wei, Cai Yong, Huang Wei, et al. Japanese Journal of Applied Physics, 2013, 52(8): 279. [12] FEI Xiang, QIAN Ke-yuan, LUO Yi(费 翔，钱可元，罗 毅). Journal of Optoelectronics·Laser(光电子·激光), 2008, 19(3): 289.
