CsI光阴极在空气中易潮解是导致实际使用时量子产额降低的重要原因。使用扫描探针显微镜观察CsI光阴极在潮解前后的表面形貌变化，发现CsI晶粒在潮解后的直径与高度变大，且CsI薄膜的覆盖率降低。对CsI光阴极潮解后的表面形貌建模，通过蒙特卡罗模拟来研究CsI光阴极的量子产额在潮解前后的变化。模拟结果显示，CsI晶粒的直径和高度变大会导致CsI光阴极的量子产额下降，并且表面形貌变化越大量子产额下降越多。因此，可以认为潮解造成CsI光阴极量子产额下降的重要原因之一是CsI光阴极表面形貌的变化。

Dehydration in air is an important factor for the reduction of quantum yield of CsI photocathode in practical use. In this paper, the surface morphology of CsI photocathode before and after deliquescence was observed by scanning probe microscopy. It is found that the diameter and height of CsI grain increase after deliquescence, and the coverage of CsI film decreases. The surface morphology of CsI photocathode after deliquescence was modeled, and the quantum yield of CsI photocathode before and after deliquescence was studied by Monte Carlo simulation. The simulation results show that the quantum yield of CsI photocathode decreases with the increase of the diameter and height of CsI grains, and the more the surface morphology changes, the more the yield decreases. Therefore, it can be considered that one of the important reasons for the decrease of CsI photocathode quantum yield is the change of surface morphology of CsI photocathode.