量子点栅敏场效应晶体管型氢气传感器性能调控及机理研究

Hydrogen has the potential to replace fossil fuels in the near future due to its clean and large energy density. Detecting hydrogen leakage in a fast, efficient and accurate way is urgently needed in hydrogen economy because of its flammable but colorless and odorless properties. Various types of hydrogen sensors already exist, but most of these sensors require high temperatures in order to function. It’s of great vitality to develop a sensor that works at room temperature. Field effect transistor (FET) hydrogen sensors show unique strengths in current modulation and amplification effects, making them ideal for low concentration hydrogen detection. Particularly, how to properly manipulate its gas adsorption activity and carrier transport characteristics is a key scientific issue that needs to be broken through. Based on our preliminary work, it is suggested to synthesize the metal oxide quantum dots as the gate materials while apply the surface-ligand engineering and interface-band engineering to modulate the gate electrical properties and synergistically enhance the hydrogen sensing properties, including sensitivity, selectivity and stability. The FET electrical modulation and amplification effects with the structure optimizing will be applied simultaneously to make sure it has suitable adsorption activity and higher charge transfer and transmission capability for hydrogen detection. Besides, a theoretical model will be established from the perspective of charge generation, transfer and transmission by analyzing the physical properties of quantum dots by in-situ characterization and supplemented by theoretical calculations. In this project, we aim to realize the low-ppm level hydrogen sensing at room temperature and systematically study on the mechanism of quantum dot gate-sensitized FET sensor via in-situ DRIFTS and DFT calculations. Based on this project, the key technologies of synergistically regulating the room-temperature response/recovery characteristics and selectivity of low- ppm level FET sensor are obtained.

氢能由于其清洁干净能量密度大等特点被认为是最具发展潜力的新能源。而氢气是一种无色无味的易燃性气体，因此对氢气泄漏检测十分必要。场效应晶体管型（FET）氢气传感器具有独特的电流调制和放大效应，特别适合于低浓度氢气检测。如何对其气体吸附活性与载流子传输特性进行合理调控是亟待突破的关键科学问题。本项目拟在前期工作基础上，运用表面配体工程和界面能带工程合成金属氧化物量子点对栅极的氢敏活性和电学特性进行针对性调制和优化，协同提升灵敏度、选择性和稳定性，同时优化FET结构合理利用其电调制和放大效应，使之对氢气检测具备合适的吸附活性和更高的电荷转移及传输能力，尝试利用原位表征分析量子点物化特性并辅以理论计算，从电荷产生、转移和传输角度建立理论模型，初步阐明量子点栅敏FET传感器室温气敏机理，据此突破协同调控FET传感器室温气敏响应活性与恢复特性及选择性的关键技术，获得适于ppm级低浓度检测的氢气传感器。

氢气传感器对于氢能产业链安全有着重要的作用。本项目利用量子点材料尺寸小，表界面物化性质易调控的特点，结合场效应晶体管（FET）电流调制的优势，构建新型室温氢气传感器。围绕量子点氢敏机理和栅敏FET型氢气传感器电学模型核心科学问题，研究并掌握调控量子点栅极敏化场效应管氢气传感器机理及关键技术，实现室温氢气传感器合成与制备。主要研究结果：（1）研究并掌握SnO2基量子点氢敏材料可控合成及表面调控技术，通过原位表征分析并结合理论计算，从分子、原子和电子层面揭示了室温氢敏效应的起源与增强机制；（2）研究并掌握栅极敏化场效应管转导机理，调控和优化FET器件结构及栅敏电极-栅绝缘层界面结构，结合量子点室温成膜优势，完成栅极敏化场效应管氢气传感器制备，实现室温氢气高性能检测。通过本项目研究，构建出基于量子点材料的场效应管氢气传感器，为新型室温氢气传感器开发提供新思路。相关研究结果以项目负责人为第一或通讯作者发表SCI论文1篇（另有两篇在审稿中），申请中国发明专利2项，项目协助培养已毕业博士生1人、在读博士生1人，已培养毕业硕士3人，另有在读博士生1人，硕士生3人。项目负责人受邀在国内外作相关口头学术报告1次，墙报2次。