一种基于亚波长尺度叉指电极的光电探测器及其制备方法

本发明提供了一种基于亚波长尺度叉指电极的光电探测器及其制备方法，所述的光电探测器包括层叠设置的衬底、叉指电极和有源层，电极层包括相对设置的两个呈齿状结构的电极片，电极片的齿状结构相对且交错设置，形成蛇形沟道；有源层与电极层接触的一侧嵌入电极层的蛇形沟道内，蛇形沟道的宽度大于等于所述有源层中载流子的扩散长度。通过亚波长尺度的电极沟道宽度更窄，电极厚度更大，将光吸收和载流子提取方向解耦合；此外，有源层形成光栅结构，通过调控局域光场强度增强工作区域的光吸收，进一步地，可通过选择有源层材料、材料颗粒尺寸或者叉指电极尺寸，调控有源层光栅结构的吸收特性，从而可以针对性的选择增强某个波长的高探测响应度。

The invention provides a photoelectric detector based on a sub-wavelength scale interdigital electrode and a preparation method thereof.The photoelectric detector comprises a substrate, an interdigital electrode and an active layer which are arranged in a stacked mode, the electrode layer comprises two electrode plates which are oppositely arranged and are of a tooth-shaped structure, and the tooth-shaped structures of the electrode plates are oppositely arranged in a staggered mode to form a snakelike channel; and the side, making contact with the electrode layer, of the active layer is embedded into the snakelike channel of the electrode layer, and the width of the snakelike channel is larger than or equal to the diffusion length of carriers in the active layer. The channel width of the sub-wavelength scale electrode is narrower, the thickness of the electrode is larger, and the light absorption direction and the carrier extraction direction are decoupled; besides, the active layer forms a grating structure, the light absorption of a working area is enhanced by regulating and controlling the intensity of a local light field, and further, the absorption characteristic of the grating structure of the active layer can be regulated and controlled by selecting the material of the active layer, the size of material particles or the size of an interdigital electrode, so that the high detection responsivity of a certain wavelength can be selectively enhanced in a targeted manner.