Crystal-phase engineering ofε-Ga_(2)O_(3) for high-performance deep UV photodetectors via MOCVD  

基于MOCVD氧化镓晶相工程的ε-Ga_(2)O_(3)高性能深紫外光电探测器

作　　者：Zhiwei Wang Hong Huang Xiaohu Hou Keju Han Weiheng Zhong Xiao Feng Haoyan Zhan Weizhen Liu Xiaolong Zhao Nan Gao Shibing Long 汪智伟;黄洪;侯小虎;韩可举;仲玮恒;冯骁;詹昊延;刘为振;赵晓龙;高南;龙世兵

机构地区：[1]School of Microelectronics,University of Science and Technology of China,Hefei 230026,China [2]Key Laboratory of UV-Emtting Materials and Technology,Ministry of Education,Northeast Normal University,Changchun 130024,China

出　　处：《Science China Materials》2025年第4期1174-1183,共10页中国科学(材料科学)(英文版)

基　　金：supported by the National Key Research and Development Program of China(2023YFB3610200 and 2024YFA1208800);the National Natural Science Foundation of China(61925110,U20A20207,62304215,and 62171426);the University of Science and Technology of China(WK2100000025,YD2100002009,YD2100002010,and YD2100002007);the China Postdoctoral Science Foundation(2023M733367);the CAS Project for Young Scientists in Basic Research(YSBR-029)。

摘　　要：Gallium oxide(Ga_(2)O_(3)),with an ultrawide bandgap corresponding to the deep ultraviolet(DUV)spectra range,provides a potential subversive scheme for the filter-free DUV photodetection.Meanwhile,the various crystal phases of Ga_(2)O_(3) provide more substrate options for achieving heteroepitaxy,with the coupling of Ga_(2)O_(3) to SiC substrates conducive to developing integrated Ga_(2)O_(3) DUV photodetectors.Phase engineering ofβ-Ga_(2)O_(3) andε-Ga_(2)O_(3) was achieved on the commercial 4H-SiC substrate via metal-organic chemical vapor deposition.According to the in-depth analysis of different Ga_(2)O_(3) growth stages,it was found thatβ-Ga_(2)O_(3) is easy to form under high-pressure growth conditions,while low-pressure conditions promote the formation ofε-Ga_(2)O_(3) at 500°C.Furthermore,the developedε-phase dominated Ga_(2)O_(3) DUV photodetector exhibits obvious advantages in high responsivity(∼639 A/W),photo-to-dark current ratio(∼2.4×10^(7)),external quantum efficiency(∼3.15×10^(5)%),and specific detectivity(∼9.62×10^(13) Jones)under 254 nm illumination.This work not only reveals the growth mechanism of Ga_(2)O_(3) films under various pressures but also ensures the great potential ofε-Ga_(2)O_(3) for highly sensitive DUV detection on the heterogeneous substrate,which is expected to expand the application of Ga_(2)O_(3) optoelectronic devices.Ga_(2)O_(3)具有与深紫外光相对应的超宽带隙,为颠覆性无滤波器深紫外光探测技术提供了一种优选光敏材料.Ga_(2)O_(3)具有多种晶相,拓宽了Ga_(2)O_(3)材料外延的衬底选择性.其中,Ga_(2)O_(3)与商用SiC衬底的耦合能够推动Ga_(2)O_(3)深紫外光电探测器的集成应用发展.本论文利用金属有机化学气相沉积技术,在4H-SiC衬底上实现了β-Ga_(2)O_(3)和ε-Ga_(2)O_(3)的精细晶相调控.通过对不同生长阶段Ga_(2)O_(3)材料特性的分析发现,生长气压具有Ga_(2)O_(3)晶相调控能力,500°C生长温度下,高生长气压易促进β-Ga_(2)O_(3)形成,而低生长气压有利于ε-Ga_(2)O_(3)生长.此外,所研制ε-Ga_(2)O_(3)深紫外光电探测器在深紫外光照下具有高响应度(~639 A/W)、大光暗电流比(~2.4×10^(7))、高外量子效率(~3.15×10^(5)%)以及高比探测率(~9.62×10^(13)Jones)等明显优势.该工作不仅深入揭示了Ga_(2)O_(3)薄膜在不同生长气压下的生长机理,而且实现了ε-Ga_(2)O_(3)与商用SiC衬底的异质集成,同时器件具有高灵敏深紫外光探测能力,为Ga_(2)O_(3)光电器件的高密度集成应用提供技术参考.

关 键 词：phase engineering c-Ga_(2)O_(3) β-Ga_(2)O_(3) MOCVD deep ultraviolet detection 

分 类 号：TN36[电子电信—物理电子学]