Correlation between photoemissive and morphological properties of KBr thin film photocathodes

TL;DR

This study investigates how the morphological features of KBr thin film photocathodes influence their photoemissive performance, revealing that increased thickness and grain density enhance photocurrent.

Contribution

It provides a detailed correlation between morphological properties and photoemissive behavior of KBr photocathodes using multiple analysis techniques.

Findings

Photocurrent increases with film thickness.

Surface roughness decreases with more layers.

Photocurrent correlates with grain density and surface coverage.

Abstract

In the present work, the morphological properties of KBr photocathodes are correlated with their photoemissive behaviour using a combination of analyzing techniques including SEM, TEM and AFM. From morphological studies, it is observed that KBr films have granular characteristics with varied average grain size and grain density. Structure and orientation of individual grains have been investigated by selected area electron diffraction technique and found to be the crystalline in nature with a face centered cubic structure. It is evident from the AFM analysis that the root mean square roughness and maximum area peak height have been decreased with the deposition of more KBr layers. The photoemission studies reveal that the resultant photocurrent is enhanced with increasing film thickness and it is directly related to the surface area coverage and grain density.