基于半导体团簇及团簇组装材料的气体传感器及其敏感机理研究

Gas sensors are one of the most important tools for people to obtain gas information，and have been playing an indispensable role in many different fields (for example, environmental monitoring and protection, chemical process control). Semiconductor clusters have outstanding physical and chemical properties, and simultaneously cluster-assembled materials, where clusters sever as building blocks, are viewed as one of functional materials with novel structural characters and properties, which provide the great possibility of developing novel efficient gas sensors. Most recently, we have made some fresh progresses in this aspect. On the foundation of the former work, using combined first-principles and classical molecular dynamics calculations, the prime goal of this research plan here is to investigate the gas sensing properties (including sensor stability, selectivity, sensitivity, and speed (response and recovery rate)) of semiconductor clusters and cluster-assembled materials, arising from the atomic- and electronic-structure levels of the interactions between gas molecules and semiconductor clusters and cluster-assembled materials. Concretely, in order to find semiconductor clusters and cluster-assembled materials with what specific composition, size, and geometry are suitable as gas sensors for certain gases detection, we will systematically investigate the following problems: the geometric structures, bonding situation, electronic transport properties and the adsorption/desorption processes etc., when some toxic and harmful gases interact with semiconductor clusters and cluster-assembled materials. The sensing properties of the above-mentioned materials will be tailored through ingredient optimization, size control, different functional factors (such as doping, defect) introduction. Furthermore, the gas sensing mechanisms of these materials will be concluded. This study will further extend the range of choice for gas sensing materials, and provide the theoretical bases and technical routes for the applications of semiconductor clusters and cluster-assembled materials in gas sensors.

气体传感器是人们获取气体信息的重要工具之一，在环境检测和保护、化工过程控制等领域发挥着重要的作用。半导体团簇具有优异的物理化学性能，并且以其为基元所形成的团簇组装材料，是一种具有奇异结构和性能的功能材料，为研制新型高效的气体传感器提供了可能。最近，我们在该方面研究上取得了一些新的进展。本项目将在此基础上，采用第一性原理和经典分子动力学方法，从气体分子与典型半导体团簇及其组装材料相互作用时的原子结构、电子结构的层面出发，通过研究它们的几何结构，成键情况，电荷转移，电子输运等问题，分析半导体团簇以及团簇组装材料的气敏特性（包括其稳定性，选择性，灵敏性和反应速度），探讨具体的何种组分，尺寸，构型的半导体团簇及其组装材料可作为气体传感器适用于某种特定气体的探测，并通过组分优化，尺度调控，掺杂等方法优化其气敏性能，探索其敏感机理，为实现半导体团簇及组装材料在气体传感器中的应用提供理论基础和技术路线。

气体传感器是人们获取气体信息的重要工具之一，在环境检测和保护，化工过程控制等领域发挥着重要的作用。半导体团簇具有优异的物理化学性能，并且以其为基元所形成的团簇组装材料，是一种具有奇异结构和性能的功能材料，为研制新型高效的气体传感器提供了可能。本项目采用第一性原理和经典分子动力学方法，从气体分子与所探究材料相互作用时的原子结构、电子结构的层面出发，通过研究它们的几何结构，成键情况，电荷转移，电子特性等问题，分析这些材料的气敏特性（包括其稳定性，选择性，灵敏性和反应速度），并通过组分优化，引入缺陷，掺杂等方法优化其气敏性能，探索其敏感机理。项目主要完成以下几方面内容：第一，类富勒烯结构的B40，Si12Au20团簇的气敏性能及其调控的理论研究，结果发现，金属掺杂或氢化是有效的气敏调控方法；第二，基于Zn12O12, W@Au12, Diazine等团簇或大分子的组装纳米结构（纳米线或二维材料）的设计和电子特性及其气敏性能的研究；第三，半导体二维材料，包括C2N, GaN, C3N, SiC, BC6N, SiC7, BC3等的气敏性能及其调控研究，分别得到了这些材料针对某些有害气体的气敏特性，例如单层C2N二维材料可以作为用以探测NO和NH3气体的气体传感器，类石墨烯状的GaN二维材料可以用以探测NO和NO2气体。第四，在研究二维单层半导体材料的气敏性能过程中，发现了部分二维材料具有优异的储氢性能，如C7N6, Si2BN, B3S等单层二维材料的优异储氢性能。本研究将扩展气敏材料的选择范围，为寻找新型高效的气敏材料提供理论基础和技术路线。