Effect of Storage at 70℃ on Photoemission Properties of GaAs Photocathode
Author(s): Shi Feng, Cheng Hongchang, Bai Xiaofeng, Yan Lei, Zhang Liandong, Science and Technology on Low Level Light Night Vision Laboratory
Pages: 686-689
Year: 2016 Issue: 6
Journal: Chinese Journal of Vacuum Science and Technology
Keyword: High-temperature storage; GaAs photocathode; Quantum efficiency; Sensitivity;
Abstract: The impact ofthe storage of GaAs photocathode（at 70℃ and 15% humidityfor 48 h）,on its emission characteristics,including the sensitivity and quantum efficiency,was experimentally evaluated by measuring the sensitivity every hour,theoretically analyzed by data-fitting and numerically calculated with software Matlab.The results show that thestorage at 70℃ of GaAs photocathode strongly affects the sensitivity and quantum efficiency.For example,as the storage time increased,the sensitivity rapidly decreased in the 1st hour,and then changed in a rapidincrease and slow-decrease mode,with a decrease by about 20%;the quantum efficiency in 500 900 nm range markedly decreased,and the decrease from 12 to 24 h was bigger than that from 0 to 12 h.Storage at 70 ℃ for 3 4 h stabilized the electronic structures at the interface of the Cs-0 surface layer and the GaAs substrate.Possible mechanisms responsible for the observations were also tentatively discussed in a thought-provoking way.
Pages: 686-689
Year: 2016 Issue: 6
Journal: Chinese Journal of Vacuum Science and Technology
Keyword: High-temperature storage; GaAs photocathode; Quantum efficiency; Sensitivity;
Abstract: The impact ofthe storage of GaAs photocathode（at 70℃ and 15% humidityfor 48 h）,on its emission characteristics,including the sensitivity and quantum efficiency,was experimentally evaluated by measuring the sensitivity every hour,theoretically analyzed by data-fitting and numerically calculated with software Matlab.The results show that thestorage at 70℃ of GaAs photocathode strongly affects the sensitivity and quantum efficiency.For example,as the storage time increased,the sensitivity rapidly decreased in the 1st hour,and then changed in a rapidincrease and slow-decrease mode,with a decrease by about 20%;the quantum efficiency in 500 900 nm range markedly decreased,and the decrease from 12 to 24 h was bigger than that from 0 to 12 h.Storage at 70 ℃ for 3 4 h stabilized the electronic structures at the interface of the Cs-0 surface layer and the GaAs substrate.Possible mechanisms responsible for the observations were also tentatively discussed in a thought-provoking way.
Related Articles