Novel Photovoltaic Phenomenon in Manganite/ZnO Heterostructure

TL;DR

This study reports a novel photovoltaic effect in a manganite/ZnO heterostructure grown on ITO glass, demonstrating reproducible rectifying behavior and light-induced current with a maximum efficiency of 0.0145%.

Contribution

It introduces a new manganite/ZnO heterostructure with low-cost fabrication showing photovoltaic properties and analyzes how film thickness affects performance.

Findings

Maximum PCE of 0.0145% at specific layer thicknesses

Light current generated under 325nm laser irradiation

Open circuit voltage of 0.04V due to internal photoemission

Abstract

In this paper, we report a novel photovoltaic phenomenon in a low cost manganite/ZnO p-n heterojunction grown on ITO glass substrate by pulsed laser depositon (PLD) under relative low growth temperature. The heterostructure ITO/La0.62Ca0.29K0.09MnO3(LCKMO)/ZnO/Al exhibits reproducible rectifying characteristics and consists of four parts: aluminum top electrode, ITO bottom electrode, manganite and ZnO semiconductor films. Moreover, the light current can generate under continuous laser ({\lambda}=325nm) irradiation. In this article, we investigate the influence of manganite and ZnO film thickness on the electrical and photoelectric characteristics of the heterostructure at room temperature. The maximum power conversion efficiency (PCE) is achieved not only when the LCKMO and ZnO layer is thin enough, but also when the full space charge layer is sufficient. We obtain the maximum value(0.0145%) of PCE when the thickness of LCKMO and ZnO layer is 25nm and 150nm, respectively. Under this condition, the open circuit voltage is 0.04V, which can be attributed to internal photoemission.