Optical and structural properties of CsI thin film photocathode

TL;DR

This study comprehensively analyzes the optical, structural, and compositional properties of cesium iodide thin film photocathodes, including their absorbance, band gap, refractive index, quantum efficiency, crystallography, surface morphology, and elemental makeup.

Contribution

It provides detailed characterization of CsI thin films using multiple techniques, offering new insights into their optical and structural properties for photocathode applications.

Findings

Optical band gap of 500 nm CsI film determined from Tauc plot.

Refractive index estimated via Swanepoel's method.

Elemental composition confirmed by EDX analysis.

Abstract

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.