Air quality is deteriorating due to continuing urbanization and industrialization.In particular,nitrogen dioxide(NO_(2))is a biologically and environmentally hazardous byproduct from fuel combustion that is ubiquitous...Air quality is deteriorating due to continuing urbanization and industrialization.In particular,nitrogen dioxide(NO_(2))is a biologically and environmentally hazardous byproduct from fuel combustion that is ubiquitous in urban life.To address this issue,we report a high-performance flexible indium phosphide nanomembrane NO_(2)sensor for real-time air quality monitoring.An ultralow limit of detection of~200 ppt and a fast response have been achieved with this device by optimizing the film thickness and doping concentration during indium phosphide epitaxy.By varying the film thickness,a dynamic range of values for NO_(2)detection from parts per trillion(ppt)to parts per million(ppm)level have also been demonstrated under low bias voltage and at room temperature without additional light activation.Flexibility measurements show an adequately stable response after repeated bending.On-site testing of the sensor in a residential kitchen shows that NO_(2)concentration from the gas stove emission could exceed the NO_(2)Time Weighted Average limit,i.e.,200 ppb,highlighting the significance of real-time monitoring.Critically,the indium phosphide nanomembrane sensor element cost is estimated at<0.1 US$due to the miniatured size,nanoscale thickness,and ease of fabrication.With these superior performance characteristics,low cost,and real-world applicability,our indium phosphide nanomembrane sensors offer a promising solution for a variety of air quality monitoring applications.展开更多
Light management and electrical isolation are essential for the majority of optoelectronic nanowire （NW） devices. Here, we present a cost-effective technique, based on vapor-phase deposition of parylene-C and subseq...Light management and electrical isolation are essential for the majority of optoelectronic nanowire （NW） devices. Here, we present a cost-effective technique, based on vapor-phase deposition of parylene-C and subsequent annealing, that provides conformal encapsulation, anti-reflective coating, improved optical properties, and electrical insulation for GaAs nanowires. The process presented allows facile encapsulation and insulation that is suitable for any nanowire structure. In particular, the parylene-C encapsulation functions as an efficient antireflection coating for the nanowires, with reflectivity down to 〈1% in the visible spectrum. Furthermore, the parylene-C coating increases photoluminescence intensity, suggesting improved light guiding to the NWs. Finally, based on this process, a NW LED was fabricated, which showed good diode performance and a clear electroluminescence signal. We believe the process can expand the fabrication possibilities and improve the devices. performance of optoelectronic nanowire展开更多
基金A.T.gratefully acknowledges the support of the Australian Research Council for a Future Fellowship(FT200100939)Discovery grant DP190101864+1 种基金A.T.also acknowledges financial support from the North Atlantic Treaty Organization Science for Peace and Security Programme project AMOXES(#G5634)ARC-NISDRG-NS210100083.
文摘Air quality is deteriorating due to continuing urbanization and industrialization.In particular,nitrogen dioxide(NO_(2))is a biologically and environmentally hazardous byproduct from fuel combustion that is ubiquitous in urban life.To address this issue,we report a high-performance flexible indium phosphide nanomembrane NO_(2)sensor for real-time air quality monitoring.An ultralow limit of detection of~200 ppt and a fast response have been achieved with this device by optimizing the film thickness and doping concentration during indium phosphide epitaxy.By varying the film thickness,a dynamic range of values for NO_(2)detection from parts per trillion(ppt)to parts per million(ppm)level have also been demonstrated under low bias voltage and at room temperature without additional light activation.Flexibility measurements show an adequately stable response after repeated bending.On-site testing of the sensor in a residential kitchen shows that NO_(2)concentration from the gas stove emission could exceed the NO_(2)Time Weighted Average limit,i.e.,200 ppb,highlighting the significance of real-time monitoring.Critically,the indium phosphide nanomembrane sensor element cost is estimated at<0.1 US$due to the miniatured size,nanoscale thickness,and ease of fabrication.With these superior performance characteristics,low cost,and real-world applicability,our indium phosphide nanomembrane sensors offer a promising solution for a variety of air quality monitoring applications.
文摘Light management and electrical isolation are essential for the majority of optoelectronic nanowire （NW） devices. Here, we present a cost-effective technique, based on vapor-phase deposition of parylene-C and subsequent annealing, that provides conformal encapsulation, anti-reflective coating, improved optical properties, and electrical insulation for GaAs nanowires. The process presented allows facile encapsulation and insulation that is suitable for any nanowire structure. In particular, the parylene-C encapsulation functions as an efficient antireflection coating for the nanowires, with reflectivity down to 〈1% in the visible spectrum. Furthermore, the parylene-C coating increases photoluminescence intensity, suggesting improved light guiding to the NWs. Finally, based on this process, a NW LED was fabricated, which showed good diode performance and a clear electroluminescence signal. We believe the process can expand the fabrication possibilities and improve the devices. performance of optoelectronic nanowire
