Polarity Control and Nanoscale Optical Characterization of AlGaN-based Multiple Quantum Wells for Ultraviolet C emitters
KAUST DepartmentMaterial Science and Engineering
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Online Publication Date2020-05-06
Print Publication Date2020-06-26
Permanent link to this recordhttp://hdl.handle.net/10754/662808
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AbstractOptical properties of AlGaN UVC multiple-quantum-wells (MQWs) with nanoscale inverted polarity domains are strongly related to the polar surfaces and nanoscale structures. In this work, the impact of pre-growth nitridation of the sapphire substrate on the polarity control of UVC MQW is highlighted and the optical properties of III- and N-polar domains were distinguished. Nanoscale cathodoluminescence peak separation of more than 30 nm is observed in lateral-polarity-structure (LPS) UVC MQWs, which is ascribed to the potential minima induced by local variation of QW thickness and Ga enrichment inside N-polar domains. After inserting an AlGaN/AlN superlattice and enhancing V/III ratio during growth, the surface morphology of N-polar domain is greatly improved, leading to a single peak emission at wavelength of 275 nm in both III- and N-polar domains, and 10-fold stronger peak intensity at the inversion domain boundary. Such understandings on the polar surface optimization and underlying reasons of peak separation enable rational design for efficient UVC emitters with improved performance.
CitationXu, H., Jiang, J., Dai, Y., Cui, M., Li, K., Ge, X., … Ye, J. (2020). Polarity Control and Nanoscale Optical Characterization of AlGaN-based Multiple Quantum Wells for Ultraviolet C emitters. ACS Applied Nano Materials. doi:10.1021/acsanm.0c00706
SponsorsThis work was supported by National Key Research and Development Program of China (2016YFB0400802), National Natural Science Foundation of China (61974149, 61704176), Key Research and Development Program of Zhejiang Province (2019C01080, 2020C01145), and Ningbo Innovation 2025 Major Project (2018B10088, 2019B10121).
PublisherAmerican Chemical Society (ACS)
JournalACS Applied Nano Materials