【目的】研究了氮化镓(GaN)和聚苯胺(PANI)复合材料在室温下对氨气(NH3)的气敏特性。【方法】以氧化镓(Ga2O3)为镓源,采用原位氮化法制备了GaN微米结构,将GaN和苯胺单体预复合后,通过原位聚合法制备了GaN/PANI气敏传感器并对样品进行了一系列表征。【结果】结果表明GaN与PANI成功复合,GaN微米结构表面与网状PANI结合,从而为气体吸附提供了更多表面位点。测试并对比纯GaN和GaN/PANI复合材料的气敏特性,在室温低湿度条件下,GaN/PANI气敏传感器对体积分数100×10-6的NH3响应度可达80.73%,是相同体积分数的NH3下纯GaN的1.7倍;另外,纯GaN的检测下限为1×10-6,而GaN/PANI复合气敏传感器的检测下限可达到1×10-9。进一步分析GaN/PANI气敏传感器的传感机理,丰富的复合材料界面显著提升GaN/PANI传感器的气敏性能。GaN/PANI气敏传感器设计为室温下检测NH3提供可靠方案。

【Purposes】This study is carriedout to discuss on the response of gallium nitride (GaN)  and polyaniline (PANI) composites to ammonia (NH ) at room temperature. 【Methods】The GaN mi‐ cron blocks were prepared by in-situ nitridation by using gallium oxide (Ga O ) as the raw material,  then GaN/PANI gas sensing prototypes were fabricated by in-situ polymerization after pre- composition between GaN and PANI. The samples were characterized.【Findings】 It is observed that  GaN micron blocks are connected to the mesh-like PANI from morphological result of GaN/PANI  gas sensor, and proved the materials are well composited. The experiments are conducted to explore  the sensing properties of pure GaN and GaN/PANI. In experimental conditions, the response of GaN/ PANI gas sensor to 100×10  NH  is 80.73%, which is 1.7 times that of pure GaN to the same con‐ centration of NH  and the limit of detection of GaN/PANI is determined to be 1×10 while that of  pure GaN is 1×10  level. The gas sensing mechanism of GaN/PANI sensors is discussed, which  provides a theoretical and experimental basis for the development of GaN composition. From this re‐ sult. The GaN/PANI gas sensor is proved to be an excellent candidate to detect NH  at room tempera‐ ture.