Heterojunctions are of essential importance for electronic sensors due to their unique properties at the junctions. However, a planar junction made of two-dimensional (2D) materials commonly suffers from slow response and irreversible recovery because of slow physisorption and desorption rates. Herein, we present a unique design of a mixed-dimensional heterojunction built from patterned growth of 3D n-type CdS nanowire arrays and p-type 2D WSe2 nanosheets for photoelectric gas sensors. This heterojunction sensor showed highly selective and reversible responses to NO2 and NH3 with detection limits of 60 and 54 ppb, respectively, under UV illumination at room temperature. Notably, the sensor exhibited an ultrafast response time of less than 1 s to 1 ppm NO2 and NH3, which outperforms most previous reports. The hybrid junction structure proposed herein will pave the way for engineering new electronic devices from a broad selection of materials to achieve improved sensing performances at room temperature.

中文翻译：

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用于超快光电气体传感器的 3D CdS 纳米线阵列与 2D WSe2 桥接的混合维异质结


异质结由于其在结点的独特特性，对于电子传感器至关重要。然而，由二维 （2D） 材料制成的平面结通常由于物理吸附和解吸速率缓慢而响应缓慢且恢复不可逆。在此，我们提出了一种独特的混合维异质结设计，该设计由用于光电气体传感器的 3D n 型 CdS 纳米线阵列和 p 型 2D WSe2 纳米片的图案化生长构建而成。在室温下的紫外光照射下，该异质结传感器对 NO2 和 NH3 表现出高选择性和可逆响应，检测限分别为 60 ppb 和 54 ppb。值得注意的是，该传感器对 NO2 和 NH3 的响应时间小于 1 秒，优于之前的大多数报告。本文提出的混合结结构将为利用多种材料设计新的电子设备铺平道路，从而在室温下实现更好的传感性能。