A ZnO micro/nanowire has been utilized to fabricate Schottky-contacted humidity sensors based on a metal-semiconductor-metal （M-S-M） structure. By means of the piezotronic effect, the signal level, sensitivity and s...A ZnO micro/nanowire has been utilized to fabricate Schottky-contacted humidity sensors based on a metal-semiconductor-metal （M-S-M） structure. By means of the piezotronic effect, the signal level, sensitivity and sensing resolution of the humidity sensor were significantly enhanced when applying an external strain. Since a higher Schottky barrier markedly reduces the signal level, while a lower Schottky barrier decreases the sensor sensitivity due to increased ohmic transport, a 0.22% compressive strain was found to optimize the performance of the humidity sensor, with the largest responsivity being 1,240%. The physical mechanism behind the observed mechanical-electrical behavior was carefully studied by using band structure diagrams. This work provides a promising way to significantly enhance the overall performance of a Schottky-contact structured micro/nanowire sensor.展开更多
We demonstrated the application of sensors for ethanol gas detection.The ZnO nanowires based sensors with interdigital electrodes were fabricated,and a platform was constructed to test the properties of the sensors.To...We demonstrated the application of sensors for ethanol gas detection.The ZnO nanowires based sensors with interdigital electrodes were fabricated,and a platform was constructed to test the properties of the sensors.To acquire better response and shorter response/recovery time,the ZnO nanowires were modified with Au.The ethanol gas sensing performance of the pure sensors and those modified with Au nanoparticles were investigated for comparison,and the optimal test temperature of 350℃ was obtained.We found that the response/recovery time for the modified sensor towards 500 ppm of the ethanol gas was reduced by 1.35 and1.42 times compared with the pure sensors,and the sensitivities towards 500 and 10 ppm of the ethanol gas were also increased by 3.18 and 1.35 times,respectively.These proved the enhancement of the Au nanoparticles in the ZnO nanowires based sensors for ethanol gas sensing.展开更多
Carbon nanotubes(CNTs) and reduced graphene oxide(r GO) nanosheets were utilized to construct glucose biosensors in combination with gold nanowire arrays(Au NWAs), and microfluidic injection analysis driven by gravity...Carbon nanotubes(CNTs) and reduced graphene oxide(r GO) nanosheets were utilized to construct glucose biosensors in combination with gold nanowire arrays(Au NWAs), and microfluidic injection analysis driven by gravity force was used to investigate the performances of as-prepared glucose biosensors. The results demonstrated glucose biosensors based on carbon nanomaterials/Au NWAs presented excellent performance at low working potential of-0.2 V versus Ag/Ag Cl(3 mol/L KCl), such as high sensitivity, good anti-interference ability and high throughput(45 h^(-1)). The glucose biosensor based on glucose oxidase(GOx)–CNT–Au NWAs showed a wide linear range from 100 to 3,000 lmol/L with a sensitivity of 4.12 l A/cm^2 mmol/L. Furthermore, the linear range and sensitivity of GOx–r GO–Au NWAs-based glucose biosensor were 50–4,000 lmol/L and 8.59 l A/(cm^2 mmol/L), respectively, which were better than those of glucose biosensor based on GOx–CNT–Au NWAs,suggesting r GO nanosheets in combination with Au NWAs being a good platform for the construction of glucose biosensors.展开更多
We demonstrate a pH sensor based on ultrasensitive nanosize Schottky junctions formed within bottom-up grown dopant-flee arrays of assembled silicon nanowires. A new measurement concept relying on a continuous gate sw...We demonstrate a pH sensor based on ultrasensitive nanosize Schottky junctions formed within bottom-up grown dopant-flee arrays of assembled silicon nanowires. A new measurement concept relying on a continuous gate sweep is presented, which allows the straightforward determination of the point of maximum sensitivity of the device and allows sensing experiments to be performed in the optimum regime. Integration of devices into a portable fluidic system and an electrode isolation strategy affords a stable environment and enables long time robust FET sensing measurements in a liquid environment to be carried out. Investigations of the physical and chemical sensitivity of our devices at different pH values and a comparison with theoretical limits are also discussed. We believe that such a combination of nanofabrication and engineering advances makes this Schottky barrier-powered silicon nanowire lab-on-a-chip platform suitable for efficient biodetection and even for more complex biochemical analysis.展开更多
文摘A ZnO micro/nanowire has been utilized to fabricate Schottky-contacted humidity sensors based on a metal-semiconductor-metal （M-S-M） structure. By means of the piezotronic effect, the signal level, sensitivity and sensing resolution of the humidity sensor were significantly enhanced when applying an external strain. Since a higher Schottky barrier markedly reduces the signal level, while a lower Schottky barrier decreases the sensor sensitivity due to increased ohmic transport, a 0.22% compressive strain was found to optimize the performance of the humidity sensor, with the largest responsivity being 1,240%. The physical mechanism behind the observed mechanical-electrical behavior was carefully studied by using band structure diagrams. This work provides a promising way to significantly enhance the overall performance of a Schottky-contact structured micro/nanowire sensor.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in UniversityProgram for New Century Excellent Talents in UniversityNational Natural Science Foundation of China(Grant Nos.51305129 and 51222508)
文摘We demonstrated the application of sensors for ethanol gas detection.The ZnO nanowires based sensors with interdigital electrodes were fabricated,and a platform was constructed to test the properties of the sensors.To acquire better response and shorter response/recovery time,the ZnO nanowires were modified with Au.The ethanol gas sensing performance of the pure sensors and those modified with Au nanoparticles were investigated for comparison,and the optimal test temperature of 350℃ was obtained.We found that the response/recovery time for the modified sensor towards 500 ppm of the ethanol gas was reduced by 1.35 and1.42 times compared with the pure sensors,and the sensitivities towards 500 and 10 ppm of the ethanol gas were also increased by 3.18 and 1.35 times,respectively.These proved the enhancement of the Au nanoparticles in the ZnO nanowires based sensors for ethanol gas sensing.
基金supported by the National Natural Science Foundation of China (51272063 and 51402081)the Natural Science Foundation of Anhui Province (1408085QB42)+1 种基金the Fundamental Research Funds for the Central Universities (JZ2014HGBZ0010)the Science and Technology Planning Project of Tongling (2015CXZX02)
文摘Carbon nanotubes(CNTs) and reduced graphene oxide(r GO) nanosheets were utilized to construct glucose biosensors in combination with gold nanowire arrays(Au NWAs), and microfluidic injection analysis driven by gravity force was used to investigate the performances of as-prepared glucose biosensors. The results demonstrated glucose biosensors based on carbon nanomaterials/Au NWAs presented excellent performance at low working potential of-0.2 V versus Ag/Ag Cl(3 mol/L KCl), such as high sensitivity, good anti-interference ability and high throughput(45 h^(-1)). The glucose biosensor based on glucose oxidase(GOx)–CNT–Au NWAs showed a wide linear range from 100 to 3,000 lmol/L with a sensitivity of 4.12 l A/cm^2 mmol/L. Furthermore, the linear range and sensitivity of GOx–r GO–Au NWAs-based glucose biosensor were 50–4,000 lmol/L and 8.59 l A/(cm^2 mmol/L), respectively, which were better than those of glucose biosensor based on GOx–CNT–Au NWAs,suggesting r GO nanosheets in combination with Au NWAs being a good platform for the construction of glucose biosensors.
文摘We demonstrate a pH sensor based on ultrasensitive nanosize Schottky junctions formed within bottom-up grown dopant-flee arrays of assembled silicon nanowires. A new measurement concept relying on a continuous gate sweep is presented, which allows the straightforward determination of the point of maximum sensitivity of the device and allows sensing experiments to be performed in the optimum regime. Integration of devices into a portable fluidic system and an electrode isolation strategy affords a stable environment and enables long time robust FET sensing measurements in a liquid environment to be carried out. Investigations of the physical and chemical sensitivity of our devices at different pH values and a comparison with theoretical limits are also discussed. We believe that such a combination of nanofabrication and engineering advances makes this Schottky barrier-powered silicon nanowire lab-on-a-chip platform suitable for efficient biodetection and even for more complex biochemical analysis.
