Abstract Two-dimensional (2D) transition metal dichalcogenides (TMDs) are promising for gas sensors owing to their large surface-to-volume ratios, but the long recovery times stemming from the slow molecular desorption have been an important limitation. In this work, we report on a sensor for nitrogen dioxide (NO2) made with a diselenide (WSe2) monolayer synthesized via chemical vapor deposition, which functions within a range of concentrations from 100 ppb to 5 ppm and at various temperatures, including room temperature. When operated at an optimized temperature of 250 °C, the WSe2 sensor exhibited the fast recovery, with the response (τres) and recovery (τrec) times of 18 s and 38 s, respectively, when exposed to 100 ppb NO2. The sensor also features high selectivity toward NO2 in the presence of other target gases, in addition to reversibility and long-term stability within 60 days. The overall characteristics of the WSe2 sensor make it suitable to monitor indoor/outdoor environments, mainly if further optimization is made with sensor design based on a model for the sensing mechanism we present in this paper.

中文翻译：

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基于 CVD 二硒化钨单层的 NO2 气体传感器

摘要 二维 (2D) 过渡金属二硫属化物 (TMD) 由于其较大的表面积与体积比而在气体传感器中很有前景，但由于分子解吸缓慢而导致的恢复时间长是一个重要的限制。在这项工作中，我们报告了一种二氧化氮 (NO2) 传感器，该传感器由通过化学气相沉积合成的二硒化物 (WSe2) 单层制成，其在 100 ppb 至 5 ppm 的浓度范围内和各种温度下起作用，包括室温. 当在 250 °C 的优化温度下运行时，WSe2 传感器表现出快速恢复，当暴露于 100 ppb NO2 时，响应 (τres) 和恢复 (τrec) 时间分别为 18 秒和 38 秒。在存在其他目标气体的情况下，该传感器还具有对 NO2 的高选择性，除了可逆性和 60 天内的长期稳定性。WSe2 传感器的整体特性使其适用于监测室内/室外环境，主要是根据我们在本文中介绍的传感机制模型对传感器设计进行进一步优化。