Recent Progress in Research on CsI Thin Film Photocathodes

doi:10.15541/jim20140346

Abstract

Abstract:

Caesium iodide (CsI) thin films have attracted much attention due to good electron transport and emission properties in the soft X-ray and extreme ultraviolet range. With the rapid development of nuclear physics, high energy physics and astrophysics, the requirements for CsI film photocathodes become increasingly severe, and it is therefore of considerable interest to develop CsI photocathodes with high quantum efficiency (QE) and stable performance. However, the internal mechanisms of QE variation and photocathode aging are not entirely clear or certain up to date. In this paper, the recent progress on CsI film photocathodes is reviewed and some controversial issues are introduced. Several perspectives are also proposed in the end.

Key words: CsI film, photocathode, quantum efficiency, moisture aging, irradiation aging, review

CLC Number:

TQ174

FAN Long, LI Yu-Kun, CHEN Tao, LI Jin, YANG Zhi-Wen, YUAN Zheng, DENG Bo, CAO Zhu-Rong, HU Xin. Recent Progress in Research on CsI Thin Film Photocathodes[J]. Journal of Inorganic Materials, 2015, 30(3): 225-232.

Figures/Tables 4

Fig. 1 (a) Parylene-N /Au /CsI semitransparence photocathode; (b) Refective CsI photocathode coated on the surface of microchannel plate (MCP)

Fig. 2 (a) SEM image of the CsI/ MgO/ MWCNTs/ Si photocathode[45]; (b) SEM image of the Si substrate patterned by colloidal lithography after lift-off process; (c)AFM image of the fresh CsI film evaporated on the Si patterned substrate; (d) AFM image of the CsI film on the Si patterned substrate exposed to ambient air for 24 h[41]

Fig. 3 SEM images of as-deposited (a), aged in ambient air (b) and extreme moisture exposed CsI films (c)[49]; Percent degradation in the yield signal of streak camera used at NIF from a 200 nm thick CsI cathode as a function of air exposure time[47]

Fig. 4 (a) AFM image of the 5 d UV-irradiated CsI photocathode[11]; (b) PEEM image of the 5 d UV-irradiated CsI photocathode[11]; (c) TEM image of the UV-irradiated CsI film[48]

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