Pd/Pt修饰的AlGaN/GaN HEMT器件氢传感特性研究

Hydrogen sensing characteristics study of Pd/Pt modified AlGaN/GaN HEMT device

制备了Pd/Pt修饰的AlGaN/GaN高电子迁移率晶体管(HEMT)器件.对器件的氢传感特性测试表明,Pd/Pt合金修饰的器件的氢响应和响应(恢复)速率要优于Pd和Pt单独修饰的器件,Pd和Pt质量比为2 mg∶1 mg的氢传感器具有最佳的氢传感性能.对吸附平衡的稳态分析进一步证实了这一结论.室温下氢体积分数为0.1%,氢气通入流速为200 mL/min时,Pd/Pt(2 mg∶1 mg)样品的电流变化为0.249 mA,响应时间和恢复时间分别为41 s和42 s.此外,测试温度增加到55℃也进一步提高了器件对氢气的响应和响应速率.

Pd/Pt modified AlGaN/GaN high electron mobility transistors(HEMT)devices were fabricated and characterized for hydrogen sensing.The comparative experiments show that the response of hydrogen and response(recovery)rate of Pd/Pt alloy modified devices are significantly higher than that of Pd and Pt individually modified device and the hydrogen sensor with Pd and Pt mass ratio of 2 mg∶1 mg is confirmed to have the optimal hydrogen sensing performance.This conclusion is further confirmed by the steady-state analysis on adsorption equilibrium.Moreover,when hydrogen volume fraction is 0.1%at room temperature and the flow rate of hydrogen is 200 mL/min,the current change of Pd/Pt(2 mg∶1 mg)sample is 0.249 mA,and the response time and recovery time is 41 s and 42 s,respectively.In addition,increasing the test temperature to 55℃also further improves the response of hydrogen and response rate.