Enhanced thermal constant B of diamond films for ultrahigh sensitivity negative temperature coefficient thermistors

具有高温度敏感常数B值的超高灵敏金刚石薄膜负温度系数热敏电阻器件

Negative temperature coefficient(NTC)thermistor plays a crucial role in science research and engineering applications for precise temperature monitoring.Although great progress has been achieved in NTC materials,enhancing sensitivity and maintaining this high sensitivity along with linearity across extensive temperature ranges remain a significant challenge.In this study,we introduce a diamondbased thermistor(DT)characterized by its outstanding sensitivity,swift response time,and broad temperature monitoring capabilities.The temperature constant B for this DT,measured from 30 to 300°C(B30/300),achieves an exceptional value of 8012 K,which notably exceeds the temperature sensing capabilities of previously reported NTC thermistors within this extensive range.Moreover,diamond’s unique thermal conductivity and stability significantly boost the response speed and durability of the DT,offering substantial advantages over traditional ceramic thermistors.The enhanced temperature-sensitive properties of the DT are attributed to the presence of impurity elements in polycrystalline diamond.Impedance analysis indicates a hopping conduction mechanism,likely involving C-H or C-N dipoles at the diamond grain boundaries.This study marks a significant leap forward in diamond thermistor technology and sheds light on the mechanisms of thermal active conduction in diamond materials.

基于负温度系数(NTC)热敏电阻的精准温度信息监测在现代科学研究及工程应用领域中至关重要.尽管目前NTC材料的敏感性能已取得显著提高,但在较宽的探测温度范围内保持高灵敏度和良好的线性度仍然面临巨大挑战.本文报道了一种具备超高灵敏度、超快响应速度和较宽温域探测能力的金刚石热敏电阻器件,在室温(30°C)至300°C的工作温度范围内,展现出极高的温度敏感常数B值(B30/300),高达8012 K.其灵敏度明显超过现有报道的同温区NTC热敏电阻.此外,金刚石优异的热导率和化学稳定性显著提高了其热敏电阻器件的响应速度和耐久性,相较于传统热敏材料具备显著的应用优势.通过表征分析发现,金刚石热敏电阻的超高灵敏度与晶界杂质元素密切相关.结合变温阻抗谱分析和霍尔效应测试,推测其热敏导电机制主要基于C-H/C-N偶极子的跳跃导电.本研究在金刚石NTC热敏技术方面所取得的进展,将为推动新型金刚石温度敏感电子器件的应用及发展提供了有力支持.