title: Variation of spectral response for exponential-doped transmission-mode GaAs photocathodes in the preparation process.
abstract: To confirm the actual effect of an exponential-doped structure on cathode performance, an exponential-doped structure was applied to the preparation of a transmission-mode GaAs photocathode, and spectral response curves after high-temperature activation, low-temperature activation, and the indium sealing process were separately measured by use of the on-line spectral response measurement system. The results show that, compared to the previously uniform-doped photocathode, the exponential-doped photocathode can obtain higher cathode performance and photoemission capability because of the built-in electric field. Nevertheless, cesium desorption and impurity of gas during the sealing process can cause the degeneration of spectral response in the entire response waveband, especially in the long-wavelength region, with the decrease in surface electron escape probability related to the adverse evolution of the surface potential barrier profile.
authors.affiliation: Institute of Electronic Engineering and Optoelectronic Technology, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Niu
authors.forename: Jijun
authors.initials: J
authors.lastname: Zou
authors.forename: Benkang
authors.initials: B
authors.lastname: Chang
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Xiong