氧化物插层调控的石墨烯/硅纳米线阵列肖特基结对硝基爆炸物气氛的半定量检测研究

It is proposed to use metal oxide as an insertion layer to regulate the Schottky junction and the light illumination to build the sensory array. Thus, the supersensitive, qualitative and semiquantitative detection of nitro-explosives vapors will be realized. It is proposed to obtain the SiNWs/TiO2(ZnO)/graphene Schottky junction to realize the optoelectronic sensing. This junction incorporates the advantages of the Si/graphene junction which has excellent sensing and optoelectronic properties, SiNWs array structure which is beneficial for the diffusion of explosive molecules. Furthermore, the TiO2 or ZnO insertion layer not only helps to regulate the Schottky barrier height, increase the adsorption energy towards nitro-explosives, but also enhances the separation of light-generated electron-hole pairs. APTS is further decorated on the junction to enhance the recognizability and sensitivity towards nitro-explosives. The underlying influence mechanisms of the sensitivity, the response time and the selectivity by the energy band structure, the crystal phase, the morphology, the surface states and the adsorption energy of the metal oxide would be fully discussed. By periodically changing the light intensity illuminated on an individual sensor, the function of the traditional sensory array can be realized by a single sensor. As a result, the qualitative and semiquantitative detection of nitro-explosives vapors can be realized by this single sensor-based sensory array. The recognition mode of this sensory array will be established at the same time. This research would shine light on the development of sensors towards trace, fast and recognizable detection of nitro-explosives vapors.

本项目将通过氧化物插层调控肖特基结并使用光照构建阵列式传感器，实现高灵敏、定性半定量检测硝基爆炸物蒸气。设计将具有高灵敏度、优异光电性能、有利于爆炸物分子扩散的石墨烯/垂直Si纳米线阵列肖特基结，及同时能够调控肖特基势垒高度、增大对硝基爆炸物的吸附能、提高光生电子—空穴对分离的TiO2或ZnO插层相结合，并进一步表面修饰APTS提高材料对硝基爆炸物的识别性和灵敏度，构建出基于石墨烯/TiO2(或ZnO)/Si纳米线阵列肖特基结的光电纳米传感材料。深入探讨氧化物插层材料的能带结构、晶型、形貌、表面状态、吸附能等因素对传感器灵敏度、响应时间、选择性的影响机制。通过周期性改变光照强度，得到由单个传感器构建的传感器阵列，从而达到对不同硝基爆炸物的定性、半定量检测。探讨对于不同硝基爆炸物指定浓度和对同一爆炸物不同浓度的识别模式。本研究将为面向硝基爆炸物蒸气痕量、快速、可识别检测的传感器开发奠定基础。

恐怖主义严重威胁社会稳定和国家安全，而爆炸物检测是反恐工作的重中之重。为了构建对爆炸物蒸气具有痕量检测、快速响应、定性半定量识别等功能的光电传感器，主要开展了三个方面的研究内容：1）以TiO2修饰SiNWs/rGO肖特基结界面，调控肖特基结势垒高度及吸附能，实现硝基爆炸物气氛的高灵敏检测；2）以ZnO修饰SiNWs/rGO肖特基结界面，以光强调制SiNWs/ZnO/rGO肖特基结，实现单个传感基元构建肖特基结人工嗅觉系统；3）以特异性比色探针分子设计为基础，以水凝胶加载探针分子形成比色检测阵列，构建比色人工嗅觉系统。.取得了五个方面的重要结果和关键数据：1）获得了TiO2或ZnO插层调节的石墨烯/氧化物/Si纳米线阵列肖特基结，掌握了其结构、形貌可控合成工艺和制备条件，掌握了优化的传感材料结构参数和测试参数；2）建立了肖特基结传感材料光电信号变化与被检测爆炸物气氛之间的内在关系，明确了光的施加会产生三种作用；据此构建了由单个光电肖特基结SiNWs/ZnO/rGO实现的人工嗅觉系统；3）优化获得了检测性能优异及抗干扰能力强的光电传感器，光电响应时间达到0.4 ms，对硝基爆炸物气氛的响应快速、高检测限和抗干扰性；4）建立了主成分分析图，实现了对8种爆炸物气氛的定性识别和典型爆炸物（DNT和黑火药）的半定量判断；5）首次构建比色人工嗅觉系统，实现了对空气中悬浮非制式爆炸物颗粒的定性检测，响应小于1 s，检测限达到pg级。.项目发表SCI论文6篇，其中，影响因子大于25的两篇，大于10的四篇；申请中国发明专利6项，其中授权2项；培养博士和硕士研究生各两名，两人获得中科院院长优秀奖。项目负责人获得2016年中国仪器仪表学会青年科技人才奖及2019年第九届新疆青年科技奖，2019年入选国家级人才计划，新疆自治区首批天山领军人才。.本研究不仅为面向硝基爆炸物蒸气痕量、快速、可识别检测的传感器开发奠定了基础，而且对解决难挥发性非制式爆炸物检测难题具有重要借鉴意义。同时，本研究将人工嗅觉系统推向了一个新高度。