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

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

Evolution of the SrTiO3–MoO3 Interface Electronic Structure: An in Situ Photoelectron Spectroscopy Study

“…thermally or electrically). 13,14 Thanks to the highly tunable transport property of STO and low activation energies of ionic migrations, a wide range of high-impact electronic devices have been realized. Particularly, resistive switching devices have been demonstrated as a promising nonvolatile memory technology where the resistance states are controlled by an external electrical field.…”

Insight into the Effects of Fe Addition on the Local Structure and Electronic Properties of SrTiO3

“…Among the large family of perovskites, strontium titanate (SrTiO 3 , abbreviated STO) is an important semiconductor with highly valued properties, such as high static dielectric constant and good insulation, 5,6 luminescence properties, 7,8 and usefulness as an oxygen gas sensor, 9,10 photocatalyst, 11,12 or photoelectrode. 13 Electronic conduction in perovskites depends mainly on the crystal structure (e.g., type and number of ions, size, and symmetry and distortion of the unit cell) and the microstructure features of the sample (usually the higher the number of grain boundaries, the lower the conductivity). This conduction occurs through the B-site network when these sites are occupied by cations capable of adopting multiple /Fe 4+ , etc).…”

Applications of Oxide Coatings in Photovoltaic Devices

“…A PV device based on a schottky junction using a SrTiO 3 crystal as the absorber has been demonstrated [51]. By using perovskite PV cells based on methylammonium lead halides (CH 3 NH 3 PbX 3 ), where X is Ch, I or Br, impressive PV cell performance has been achieved by several groups.…”

“…Examples of well-known perovskites include SrTiO 3 [6,51,52], YTiO 3 [6], LaTiO 3 [6], LaAlO 3 [52], BiFeO 3 [53] and KNbO 3 [53]. SrTiO 3 is transparent and is nominally insulating but becomes an n-type conductor due to vacancies near the Ti sites [6,51]. BiFeO 3 and KNbO 3 have smaller bandgap energies that lie in the visible and near infrared region, respectively, making them interesting for use as a photovoltaic absorber [53].…”

“…As a result of crystalline distortions caused mainly by oxygen vacancies, the electronic and magnetic properties are widely variable. Examples of well-known perovskites include SrTiO 3 [6,51,52], YTiO 3 [6], LaTiO 3 [6], LaAlO 3 [52], BiFeO 3 [53] and KNbO 3 [53]. SrTiO 3 is transparent and is nominally insulating but becomes an n-type conductor due to vacancies near the Ti sites [6,51].…”