光激发ZnO/In₂O₃异质结快速响应–恢复特性

Light-Induced Rapid Response and Recovery Characteristics of ZnO/In₂O₃ Heterostructures

摘要: 气体传感器作为探测特定环境气体信息的关键器件，在环境监测、医疗诊断、工业安全及物联网等领域具有广阔的应用前景。半导体气体传感器主要依赖敏感材料与气体之间的相互作用实现气体识别，深入理解这一相互作用机制对于设计高性能传感器具有重要意义。室温气体传感器普遍存在选择性差、响应恢复速度慢的不足，严重制约了其实用化进程。针对上述挑战，研究通过水热法合成了不同Zn/In摩尔比的ZnO/In₂O₃异质结材料，结果表明异质结的构建对缩短响应恢复时间具有显著作用。实验结果表明，Zn/In摩尔比为2:1的ZnO/In₂O₃异质结材料响应时间为10 s，恢复时间为16 s。光照条件下响应恢复时间的缩短主要归因于异质结结构促进了光生载流子的分离与传输，从而加速了表面气体分子的吸附与脱附过程。该实验为构建室温光照下具有快速响应–恢复特性的高性能气体传感器提供了一种可行的设计思路。

Abstract: As key devices for detecting specific environmental gas information, gas sensors hold broad application prospects in fields such as environmental monitoring, medical diagnosis, industrial safety, and the Internet of Things. Semiconductor gas sensors primarily rely on the interaction between sensitive materials and gases to achieve gas identification; therefore, a thorough understanding of this interaction mechanism is crucial for designing high-performance sensors. Room-temperature gas sensors generally suffer from poor selectivity and slow response recovery times, which severely hinder their practical application. To address these challenges, this study synthesized ZnO/In₂O₃ heterojunction materials with different Zn/In molar ratios via the hydrothermal method. The results indicate that the construction of the heterojunction plays a significant role in shortening the response recovery time. Experimental results show that the ZnO/In₂O₃ heterojunction material with a Zn/In molar ratio of 2:1 has a response time of 10 s and a recovery time of 16 s. The reduction in response-recovery time under illumination is primarily attributed to the heterojunction structure, which facilitates the separation and transport of photo-generated carriers, thereby accelerating the adsorption and desorption processes of surface gas molecules. These experimental findings provide a feasible design approach for developing high-performance gas sensors with rapid response-recovery characteristics under room-temperature illumination.