Improvement of crystallinity and luminescence of GaN-based laser diode structure with suppressed curvature variation in active layers
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The influence of curvature variation on the crystallinity and luminescence of GaN-based blue laser diode (LD) structure is comprehensively investigated during the growth of InGaN/GaN active layers. Compared with InGaN/GaN multiple quantum well (MQWs) grown by the conventional 2-temperature deposition, curvature variation is successfully suppressed and a much gentler deformation from wells to barriers is obtained by employing same-temperature deposition method (STDM). With less curvature fluctuation, the V-pit density of InGaN/GaN MQWs grown on sapphire is effectively decreased from 4.5 × 108/cm2 to 2.8 × 108/cm2 with average root-mean-square roughness of 0.55 nm, while threading dislocation density of the GaN-based LD structures grown on FS-GaN is also reduced from 5.9 × 106/cm2 to 1.6 × 106/cm2. Additionally, an ~ 7 nm redshift in photoluminescence emission for LD structure is achieved, accompanied by a ~ 6 times higher emission intensity. A more uniform distribution of emission wavelength along the radial direction is observed and the full width at half maximum is also narrowed, indicating that the STDM is advantageous to effectively eliminate the negative influence of curvature variation and contribute to fabricating high-performance GaN-based light-emitting diodes and LDs.
KeywordsInGaN/GaN MQWs Laser diode structure Curvature variation Same-temperature deposition
The authors gratefully acknowledge the supports of senior engineers Lianhong Kang, Guoliang Dong and Tianbao Zhou from Sino-semiconductor Technologies Co., Ltd.
- Belousov, M., Volf, B.: Method and apparatus for measuring the curvature of reflective surfaces. US Patent US7570368 B2 (2009)Google Scholar
- Hoffmann, V., Knauer, A., Brunner, C., Einfeldt, S., Weyers, M., Tränkle, G., Haberland, K., Zettler, J.T., Kneissl, M.: Uniformity of the wafer surface temperature during MOVPE growth of GaN-based laser diode structures on GaN and sapphire substrate. J. Cryst. Growth 315(1), 5–9 (2011). https://doi.org/10.1016/j.jcrysgro.2010.09.048 ADSCrossRefGoogle Scholar
- Liu, J., Zhang, L., Li, D., Zhou, K., Cheng, Y., Zhou, W., Tian, A., Ikeda, M., Zhang, S., Yang, H.: GaN-based blue laser diodes with 2.2 W of light output power under continuous-wave operation. IEEE Photonics Technol. Lett. (99), 1–1 (2017)Google Scholar
- Oliver, R.A., Massabuau, F.C.P., Kappers, M.J., Phillips, W.A., Thrush, E.J., Tartan, C.C., Blenkhorn, W.E., Badcock, T.J., Dawson, P., Hopkins, M.A.: The impact of gross well width fluctuations on the efficiency of GaN-based light emitting diodes. Appl. Phys. Lett. 103(14), 141114 (2013)ADSCrossRefGoogle Scholar
- Strauss, U., Koenig, H.: GaInN laser diodes from 440 to 530 nm: a performance study on single-mode and multi-mode R&D designs. Proc. SPIE 10123, 101230A (2017)Google Scholar