Comparison of quantum and collection efficiency of field‐assisted uniform‐doping and exponential‐doping GaN nanowire cathodes. (8th January 2020)

• Record Type: Journal Article
• Authors: Lu, Feifei; Liu, Lei; Tian, Jian
• Is Part Of: International journal of energy research. Volume 44:Number 3(2020)
• Page Start: 1751
• Page End: 1760
• Publication Date: 2020-01-08
• Subjects: electric field -- electron collection -- GaN nanowires photocathode; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.5013
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: The field‐assisted method is proposed to increase electron capture of the GaN nanowire cathode. We deduce the photoemission or electron collection efficiencies of the field‐assisted uniform‐doping and exponential‐doping cathodes using the diffusion‐drift formula. Results show that the external electric field has a significantly better collection efficiency for uniform‐doping nanowire cathodes than that of exponential‐doping. In cathodes without a build‐in field, quantum efficiency and collection efficiency reached a maximum at incident angles of 65° and 45°, and field intensity of 0.1 and 0.7 V/μm, respectively. The external electric field also contributes to the polarization of GaN nanowires. The field‐assisted GaN NWAs (nanowirearray) cathode could improve the photoemission performance and are expected to be realized in the follow‐up experiment. Abstract : For improving the photoemission capability and electron capture capability of the GaN nanowire cathode, external electric field is proposed, which has a better benefit for uniform‐doping nanowire cathodes than exponential‐doping. For uniform‐doping GaN nanowires, the collection efficiency reached a maximum at field intensity of 0.7 V/μm. These simulations can provide an interesting attempt for the realization of nano‐based GaN electron sources and are expected to improve the photoemission performance.