Author(s): Cui, BY (Cui, Bingyue); Yang, J (Yang, Jie); Gao, XF (Gao, Xingfa); He, JH (He, Jiaheng); Liu, Z (Liu, Zhe); Cheng, Z (Cheng, Zhe); Zhang, Y (Zhang, Yun)

Source: SEMICONDUCTOR SCIENCE AND TECHNOLOGY Volume: 39  Issue: 3 Article Number: 03LT01  DOI: 10.1088/1361-6641/ad238b  Published: MAR 1 2024 

Abstract: This work demonstrated a deep-ultraviolet (DUV) LED with an Al-graded p-AlGaN contact layer above the electron blocking layer to alleviate p-type contact resistance, the asymmetry of carriers transport, and the polarization effect. The fitting results from the ABC + f(n) model revealed that the LED has a higher radiative recombination coefficient than the conventional structures ever reported, which contributes to a lower carrier lifetime. The light output power of the LED at 350 mA is 44.71 mW, the peak external quantum efficiency (EQE) at 22.5 mA is 5.12%, the wall-plug efficiency at 9 mA is 4.40%. The 3 dB electrical-to-optical modulation bandwidth of the graded p-AlGaN contact layer LED is 390 MHz after impedance matching. In short, this study provides an in-depth analysis of the physical mechanism of the enhanced EQE and decreased carrier lifetime of DUV LEDs with Al-graded AlGaN as a p-type contact layer.

Accession Number: WOS:001163325100001

ISSN: 0268-1242

eISSN: 1361-6641