The effect of lateral growth of self-assembled GaN microdisks on UV lasing action  

作　　者：Zhiwei Si Zongliang Liu Xiaoxuan Wang Chunxiang Xu Wei Lin Xiaoxuan Luo Feng Li Xiaoming Dong Shunan Zheng Xiaodong Gao Jianfeng Wang Ke Xu 

机构地区：[1]School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China [2]Suzhou Institute of Nano-tech and Nano-bionics,Chinese Academy of Sciences,Suzhou 215123,China [3]Suzhou Nanowin Science and Technology Co,Ltd.,Suzhou 215123,China [4]Shenyang National Laboratory for Materials Science,Jiangsu Institute of Advanced Semiconductors,Suzhou 215123,China [5]State Key Laboratory of Bioelectronics,School of Biological Science and Medical Engineering,Southeast University,Nanjing 210096,China [6]Key Laboratory for Physical Electronics and Devices of the Ministry of Education&Shaanxi Key Lab of Information Photonic Technique,School of Electronic Science and Engineering,Faculty of Electronic and Information Engineering,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Nano Research》2023年第8期11096-11106,共11页纳米研究（英文版）

基　　金：This work was supported by the National Key R&D Program of China(No.2021YFB3602000);the Fundamental Research Funds for the Central Universities(No.WK5290000003).

摘　　要：There are significant differences in the extent of impurity incorporation on different crystallographic directions of GaN microstructures,and the impurity-related deep energy level behavior will have a significant impact on device performance.However,a comprehensive understanding of the effect of lateral growth on device performance has not been achieved due to the lack of comprehensive spatial distribution characterization of the optical behavior and impurity incorporation in GaN microstructures.We present a comprehensive study of the optical behavior and growth mechanism of self-assembled GaN microdisks using nanoscale spatially resolved cathodoluminescence(CL)mapping.We have found a clear growth orientation-dependent optical behavior of the lateral and vertical growth sectors of self-assembled GaN microcrystals.The lateral growth sector,i.e.,the{101¯1}-growth sector,forms six side facets of the microdisk and shows significant near-bandgap emission(NBE)and weak deep energy level luminescence.Cavity effect enhanced emission was found for the first time in such a truncated hexagonal Na-flux GaN microdisk system with an ultra-smooth surface(Ra<0.7 nm)and low stress.The self-assembled microdisk shows significant ultraviolet(UV)lasing action(main lasing peak wavelength 370.9 nm,quality factor 1278,threshold 6×10^(4)μJ/cm^(2))under pulsed optical pumping.We believe that the appearance of UV lasing action may be related to the light limitation on the six side facets of the lateral growth of the GaN microdisk,the high structural quality,the low content of deep energy level defects,the low surface roughness,and the low stress.

关 键 词：homogeneous lateral epitaxy spatially resolved cathodoluminescence deep energy level GaN microdisk LASING 

分 类 号：TN24[电子电信—物理电子学]