摘要
在图形化蓝宝石衬底掺杂渐变的氮化镓(GaN)外延片上制备了肖特基型紫外探测器。与传统结构器件相比,该器件表现出显著改善的电学和光学特性:(1)室温下,当偏压为-5V时具有极低的暗电流密度~1.3×10-8 A/cm^2;(2)在零偏压情况下,紫外/可见光抑制比为~4.2×10~3,最高的响应度为~0.147A/W,最大外量子效率为~50.7%,甚至在深紫外波段(250~360nm)平均量子效率也大于40%;(3)平均开启和关闭瞬态响应常数分别为115μs和120μs,基本不随偏压变化,且具有很好的热稳定性;(4)零偏压下热噪声限制的极限探测率为~5.5×10^(13)cm·Hz^(1/2)/W。
A GaN-based Schottky-barrier ultraviolet photodetectors(PDs)with graded doping was prepared on patterned sapphire substrates.Compared with the conventional structure devices,the fabricated PDs show significant improvements in both of the electrical and optoelectronic properties:(1)At room temperature,it exhibits a very low dark current density of-1.3×10^-8 A/cm^2 under a bias of-5V;(2)Under zero bias,it has a large ultraviolet/visible rejection ratio of-4.2×10^3,a highest photo-responsivity of-0.147A/W and a maximum external quantum efficiency of-50.7%.Even in deep-UV region(250-360nm),the average quantum efficiency is still greater than 40%;(3)The average rise and fall time constants are estimated to be-115μs and 120μs respectively,which are almost unchanged with the increasing bias and temperature,showing good thermal stability;(4)The specific detectivity limited by the thermal noise is determined to be-5.5×10^13 cm·Hz^1/2/W at 0V.
出处
《固体电子学研究与进展》
CSCD
北大核心
2017年第2期119-123,共5页
Research & Progress of SSE
基金
国家自然科学基金资助项目(61504050)
江苏省自然科学基金资助资助项目(BK20130156
BK20140168
BK20150158)
2015年度普通高校研究生科研创新计划项目(KYLX15_1195)
关键词
图形化蓝宝石衬底
氮化镓肖特基型紫外探测器
光电特性
热噪声
patterned sapphire substrates(PSS)
GaN Schottky UV photodetectors
optoelec tronic performance
thermal noise