Effect of Incident Light on Transport Properties of Pulsed Laser Deposited Manganite Thin Films

Abstract

In this communication, we report the results of different light illumination on electrical transport properties of La0.67Ca0.33Mn0.9Ga0.1O3 (LCMGO) thin films grown on Si (100) ( n-type phosphorus-doped) wafer using Pulsed Laser Deposition (PLD) System. The variation in deposition time changes the thickness of the films. X-ray Diffraction (XRD) reveals the polycrystalline structure of LCMGO thin films. The cross-sectional SEM were taken to determine the thickness of the films with changing deposition time. Atomic Forced Micrographs (AFM) show that island type grains diffuse into one another to form a more uniform distribution of grains as the thickness of the film increases. The charge transport properties have been studied using the I-V measurement at LCMGO/Si interfaces. I-V measurement shows the backwards-diode like the behaviour of the LCMGO/Si p-n junction. The reverse bias current changes under the influence of different incident light illumination. The built-in electric field is generated at the interface when the film was illuminated with UV light. The tunnelling process for backward diode like p-n junction is explained using a modified Simmons model.