论文标题
底物对WSE $ _2 $ photodeTector的速度限制因子的影响
Substrate Effects on the Speed Limiting Factor of WSe$_2$ Photodetectors
论文作者
论文摘要
我们研究了通用玻璃和柔性聚酰亚胺基板上WSE $ _2 $晶体的时间分辨光电响应，以确定介电环境对光电视速度的影响。我们表明，不同的底物材料可以改变速度限制机制：虽然聚酰亚胺上的探测器受到RC的限制，但玻璃上的探测器受到较慢的激发量扩散过程的限制。我们将其归因于与聚酰亚胺相比，玻璃较高的介电筛选引起的金属电极/WSE2界面处的耗竭层的缩短。玻璃上的光电检测器显示出可调的带宽，随着电场的增加，可以增加到2.6 MHz。
We investigate the time-resolved photoelectric response of WSe$_2$ crystals on common glass and flexible polyimide substrates to determine the effect of the dielectric environment on the speed of the photodetectors. We show that varying the substrate material can alter the speed-limiting mechanism: while the detectors on polyimide are RC limited, those on glass are limited by slower excitonic diffusion processes. We attribute this to a shortening of the depletion layer at the metal electrode/WSe2 interface caused by the higher dielectric screening of glass compared to polyimide. The photodetectors on glass show a tunable bandwidth which can be increased to 2.6 MHz with increasing the electric field.
