Tunable photovoltaic effect and solar cell performance of self-doped perovskite SrTiO3

K X Jin,Z L Wang,Y F Li,X W Sun,A K K Kyaw,H Y Peng,Y L Jin,W N Lin,Tom Wu,C Soci,K J Jin

doi:10.1063/1.4766279

Abstract

We report on the tunable photovoltaic effect of self-doped single-crystal SrTiO3 (STO), a prototypical perovskite-structured complex oxide, and evaluate its performance in Schottky junction solar cells. The photovaltaic characteristics of vacuum-reduced STO single crystals are dictated by a thin surface layer with electrons donated by oxygen vacancies. Under UV illumination, a photovoltage of 1.1 V is observed in the as-received STO single crystal, while the sample reduced at 750 °C presents the highest incident photon to carrier conversion efficiency. Furthermore, in the STO/Pt Schottky junction, a power conversion efficiency of 0.88% was achieved under standard AM 1.5 illumination at room temperature. This work establishes STO as a high-mobility photovoltaic semiconductor with potential of integration in self-powered oxide electronics.

Highlights

In a typical bulk solar cell, a build-in field at the p-n or Schottky junction separates the photo excited electron-hole pairs, producing the photovoltage and the photocurrent.[1]
In spite of being one of the most prominent transition metal oxides (TMOs), strontium titanate (STO) has not been considered as an active material in bulk solar cells which need to operate in a broad range of wavelengths in the visible regime
Under UV light illumination, a large photovoltage of ∼1.1 V was observed in the as-received STO single crystals, while the sample reduced at 750 ◦C presents the highest photocurrent thanks to the high mobility in semiconducting STO

Summary

Introduction

In a typical bulk solar cell, a build-in field at the p-n or Schottky junction separates the photo excited electron-hole pairs, producing the photovoltage and the photocurrent.[1]. For the self-doped STO devices with interdigitated electrodes, a power conversion efficiency of 0.88% was achieved under standard AM 1.5 solar illumination at room temperature.

Results

Conclusion