The Internet of things for environment monitoring requires high performance with low power-consumption gas sensors which could be easily integrated into large-scale sensor network.While semiconductor gas sensors have ...The Internet of things for environment monitoring requires high performance with low power-consumption gas sensors which could be easily integrated into large-scale sensor network.While semiconductor gas sensors have many advantages such as excellent sensitivity and low cost,their application is limited by their high operating temperature.Two-dimensional(2D)layered materials,typically molybdenum disulfide(MoS2)nanosheets,are emerging as promising gas-sensing materials candidates owing to their abundant edge sites and high in-plane carrier mobility.This work aims to overcome the sluggish and weak response as well as incomplete recovery of MoS2 gas sensors at room temperature by sensitizing MoS2 nanosheets with PbS quantum dots(QDs).The huge amount of surface dangling bonds of QDs enables them to be ideal receptors for gas molecules.The sensitized MoS2 gas sensor exhibited fast and recoverable response when operated at room temperature,and the limit of NO2 detection was estimated to be 94 ppb.The strategy of sensitizing 2D nanosheets with sensitive QD receptors may enhance receptor and transducer functions as well as the utility factor that determine the sensor performance,offering a powerful new degree of freedom to the surface and interface engineering of semiconductor gas sensors.展开更多
Integrated sensor combines multiple sensor functions into a single unit,which has the advantages of miniaturization and better application potential.However,limited by the sensing platforms of the sensor and the selec...Integrated sensor combines multiple sensor functions into a single unit,which has the advantages of miniaturization and better application potential.However,limited by the sensing platforms of the sensor and the selectivity of the sensitive film,there are still challenges to realize multi-component gas detection in one unit.Herein,a principle integration method is proposed to achieve the multi-component gas detection based on the acoustics-electricity-mechanics coupling effect.The electrical and mechanical properties of the Bi_(2)S_(3)nanobelts materials in different atmospheres indicate the possibility of realizing the principle integration.At the same time,the surface acoustic wave(SAW)sensor as a multivariable physical transducer can sense both electrical and mechanical properties.Upon exposure to 10 ppm NO_(2),NH_(3),and their mixtures,the integrated SAW gas sensor shows a 4.5 kHz positive frequency shift(acoustoelectric effect),an 11 kHz negative frequency shift(mechanics effects),and a reduced 4 kHz negative frequency shift(acoustics-electricity-mechanics coupling effect),respectively.Moreover,we realize wireless passive detection of NO_(2)and NH_(3)based on the SAW sensor.Our work provides valuable insights that can serve as a guide to the design and fabrication of single sensors offering multi-component gas detection via different gas sensing mechanisms.展开更多
基金National Natural Science Foundation of China(Nos.61861136004 and 61922032).
文摘The Internet of things for environment monitoring requires high performance with low power-consumption gas sensors which could be easily integrated into large-scale sensor network.While semiconductor gas sensors have many advantages such as excellent sensitivity and low cost,their application is limited by their high operating temperature.Two-dimensional(2D)layered materials,typically molybdenum disulfide(MoS2)nanosheets,are emerging as promising gas-sensing materials candidates owing to their abundant edge sites and high in-plane carrier mobility.This work aims to overcome the sluggish and weak response as well as incomplete recovery of MoS2 gas sensors at room temperature by sensitizing MoS2 nanosheets with PbS quantum dots(QDs).The huge amount of surface dangling bonds of QDs enables them to be ideal receptors for gas molecules.The sensitized MoS2 gas sensor exhibited fast and recoverable response when operated at room temperature,and the limit of NO2 detection was estimated to be 94 ppb.The strategy of sensitizing 2D nanosheets with sensitive QD receptors may enhance receptor and transducer functions as well as the utility factor that determine the sensor performance,offering a powerful new degree of freedom to the surface and interface engineering of semiconductor gas sensors.
基金supported by the National Natural Science Foundation of China(No.61922032)We thank the Program for the Academic Frontier Youth Team of Huazhong University of Science and Technology(HUST)(No.2018QYTD06)the Innovation Fund of Wuhan National Laboratory for Optoelectronics.
文摘Integrated sensor combines multiple sensor functions into a single unit,which has the advantages of miniaturization and better application potential.However,limited by the sensing platforms of the sensor and the selectivity of the sensitive film,there are still challenges to realize multi-component gas detection in one unit.Herein,a principle integration method is proposed to achieve the multi-component gas detection based on the acoustics-electricity-mechanics coupling effect.The electrical and mechanical properties of the Bi_(2)S_(3)nanobelts materials in different atmospheres indicate the possibility of realizing the principle integration.At the same time,the surface acoustic wave(SAW)sensor as a multivariable physical transducer can sense both electrical and mechanical properties.Upon exposure to 10 ppm NO_(2),NH_(3),and their mixtures,the integrated SAW gas sensor shows a 4.5 kHz positive frequency shift(acoustoelectric effect),an 11 kHz negative frequency shift(mechanics effects),and a reduced 4 kHz negative frequency shift(acoustics-electricity-mechanics coupling effect),respectively.Moreover,we realize wireless passive detection of NO_(2)and NH_(3)based on the SAW sensor.Our work provides valuable insights that can serve as a guide to the design and fabrication of single sensors offering multi-component gas detection via different gas sensing mechanisms.
