SnO_2-LiZnVO_4系湿敏元件电容特性分析

Capacitive characteristic analysis of SnO_2-LiZnVO_4 system humidity sensor

采用共沉淀法制备SnO2-LiZnVO4系湿敏材料,研究了LiZnVO4的掺杂量对材料湿敏电容的影响。结果表明:LiZnVO4的掺杂量,环境的相对湿度(RH)、测试信号频率对湿敏电容有较大影响。当x(LiZnVO4)为10%时,可使材料具有合适的低湿电容和灵敏度。在100Hz下,当环境的RH从33%上升到93%时,SnO2-LiZnVO4系湿敏材料制备的湿敏元件的电容增量可达起始值的2300%,显示出较高的电容湿度敏感性。湿敏元件的电容响应时间约为54s,恢复时间约为60s。湿滞约为RH6%。

SnO2-LiZnVO4 system humidity sensing materials were prepared by co-precipitation method. The influence of LiZnVO4-doped amount on humidity sensing capacitance of this material was studied. The results show that the humidity sensing capacitance strongly depends on the LiZnVO4-doped amount, relative humidity （RH） of environment, and frequency of measured signal. This humidity sensing material with proper capacitance at lower humidity and sensitivity can be made by doped amount of 10% of LiZnVO4 （mole fraction）. The capacitance increment of humidity sensor prepared by humidity sensing material of SnO2-LiZnVO4 system is 2 300% of its initial value when RH of environment is increased from 33% to 93% at 100 Hz, indicating higher capacitance humidity sensitivity. Of the humidity sensor, the capacitance response time for RH-increasing process is about 54 s and recovery time for RH-decreasing process is about 60 s, and the hysteresis is about RH 6%.