Optical and structural properties of CsI thin film photocathode

In the present work performance of cesium iodide thin film photocathode is studied in detail. The optical absorbance of cesium iodide thin films have been analyzed in the spectral range of 190 nm to 900 nm. The optical band gap energy of 500 nm thick cesium iodide film is calculated using Tauc plot from absorbance data. Refractive index is estimated from envelope plot of transmittance data using Swanepoel's method. Absolute quantum efficiency measurement has been carried out in the wavelength range of 150 nm to 200 nm. Crystallographic nature and surface morphology are investigated by X-ray diffraction, transmission electron microscopy and atomic force microscopy techniques. In addition, elemental composition result gained by energy dispersive X-ray analysis is also reported in the present work.