Abstract：
Gas sensors based on ambipolar materials offer significant advantages in reducing the size of the analytical system and enhancing its efficiency. Here, bilayer heterojunction devices are constructed using different octafluorinated phthalocyanine complexes, with Zn and Co as metal centers, combined with a lutetium bisphthalocyanine complex (LuPc2). Stable p-type behavior is observed for the ZnF8Pc/LuPc2 device under both electron-donating (NH3) and -oxidizing (NO2 and O3) gaseous species, while the CoF8Pc/LuPc2 device exhibits n-type behavior under reducing gases and p-type behavior under oxidizing gases. The nature of majority of the charge carriers of Co-based devices varies depending on the nature of target gases, displaying an ambipolar behavior. Both heterojunction devices demonstrate stable and observable response toward all three toxic gases in the sub-ppm range. Remarkably, the Co-based device is highly sensitive toward ammonia with a limit of detection (LOD) of 200 ppb, whereas the Zn-based device demonstrates exceptional sensitivity toward oxidizing gases, with excellent LOD values of 4.9 and 0.75 ppb toward NO2 and O3, respectively, which makes it one of the most effective organic heterojunction sensors reported so far for oxidizing gases.
摘要：
基于双极性材料的气体传感器在减小分析系统的尺寸和提高其效率方面具有显著的优势。这里,使用不同的八氟化酞菁配合物构造双层异质结器件，以Zn和Co为金属中心，与双酞菁配合物(LuPc2)结合。在供电子（NH3）和氧化（NO2和O3）气态物质下，ZnF8Pc/LuPc2器件均观察到稳定的p型行为，而CoF8Pc/LuPc2器件在还原气体下表现出n型行为，在氧化气体下表现出p型行为。Co基器件的大多数电荷载流子的性质根据目标气体的性质而变化。显示双极行为。两种异质结器件均表现出对所有三种亚ppm范围内的有毒气体的稳定且可观察到的响应。值得注意的是,Co基设备对氨高度敏感，检测限（LOD）为200ppb，而锌基器件对氧化气体表现出非凡的敏感性，对NO2和O3的LOD值分别为4.9和0.75ppb，这使得它成为迄今为止报道的用于氧化气体的最有效的有机异质结传感器之一。
