Decoupled modulation of the degree of optical polarization and emission wavelength in far-UVC-LEDs: A staggered quantum wells strategy
Abstract
The inherently poor light extraction efficiency severely limits the application of AlGaN-based far-ultraviolet-C (far-UVC) light emitting diodes (LEDs) (<240 nm). This originates from the ultra-high Al composition of quantum wells required for short-wavelength emission, which induces a transverse magnetic dominant optical polarization and inevitably causes serious total internal reflection. To reconcile the degree of optical polarization (DOP) and emission wavelength, a function divisional strategy utilizing staggered Al composition quantum wells is proposed in this architecture, where the low-Al and high-Al layers separately govern the DOP and wavelength through the modulation of valence and conduction band, respectively. Consequently, the DOP of quantum wells is reversed from −40% to ∼16% at an emission wavelength of 236 nm, enabling transverse electric-dominant vertical emission. Thanks to it, the far-UVC-LEDs exhibit a light output power of 3.13 mW at 400 mA and a peak wall plug efficiency of 0.13% at 100 mA, showing enhancements severally of 12.2% and 34.7% over the conventional structures. This strategy is highly compatible with commercial metal-organic chemical vapor deposition, offering a robust pathway for high-performance far-UVC-LEDs.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (19)
C. Z. Ji
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
J. Lang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
F. J. Xu
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
J. M. Wang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
H. Yang
E. F. Zhang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
L. S. Zhang
Beijing SinoGaN Semiconductor Technology Co., Ltd. 2 , Beijing 101399,
Z. Y. Zhang
F. Y. Tan
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
J. C. Zhang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
H. S. Qi
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
W. Y. Li
X. Yan
M. Yang
Jiangsu Nata Opto-electronic Material Co., Ltd. 3 , Suzhou 215128,
X. N. Kang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
X. L. Yang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
N. Tang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
X. Q. Wang
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,
B. Shen
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University 1 , Beijing 100871,