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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 Schottky-type UV detector was fabricated on a patterned sapphire substrate with a graded gallium nitride (GaN) epitaxial wafer. The device exhibits significantly improved electrical and optical properties compared to conventional structured devices: (1) Very low dark current density of ~ 1.3 × 10 -8 A / cm 2 at room temperature at -5 V bias ; (2) The UV / Vis rejection is ~ 4.2 × 10 ~ 3 at zero bias, the highest responsivity is ~ 0.147A / W and the maximum external quantum efficiency is ~ 50.7% (3) The average on and off transient response constants are 115μs and 120μs, respectively, which are basically unchanged with the bias voltage and have good thermal stability. (4) Zero bias voltage The detection limit of the lower thermal noise limit is ~ 5.5 × 10 ~ (13) cm · Hz ~ (1/2) / W.