Growth of InGaN-based blue-LED on AlN/sapphire sputtered with different oxygen flow rate

Abstract

Indium Gallium Nitride based blue light-emitting diodes (LEDs) suffer from insufficient crystal quality and serious efficiency droop in large forward current. In this paper, the InGaN-based blue LEDs are grown on sputtered aluminum nitride (AlN) films to improve the device light power and weaken the efficiency droop. The effects of oxygen flow rate on the sputtering of AlN films on sapphire and device performance of blue LEDs are studied in detail. The mechanism of external quantum efficiency improvement is related to the change of V-pits density in multiple quantum wells. The external quantum efficiency of 66% and 3-V operating voltage are measured at a 40-mA forward current of with the optimal oxygen flow rate of 4 SCCM.

Graphical abstract

Keywords

light-emitting diode (LED) / sputtered aluminum nitride (AlN) / physical vapor deposition (PVD) / metal-organic chemical vapor deposition (MOCVD)

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Acknowledgments

The work was supported by the National Key Research and Development Program of China (No. 2019YFA0708203), the Center of Micro-Fabrication and Characterization (CMFC) of WNLO, Chinese Academy of Sciences (No. IIMDKFJJ-17-09), the National Natural Science Foundation of China (Grant Nos. 61704062, 61774065, and 61704176), and the China Postdoctoral Science Foundation (No. 2016M602287).

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