Reduced Leakage Current and Enhanced Photovoltaic Effect in Zn-Doped BiFeO₃ Thin Films

Abstract

Zn-doped BiFeO 3 (BFO) thin films with compositional formula BiFe 1−x Zn x O 3 (x = 0, 0.1, and 0.2) have been epitaxially grown on SrRuO 3 buffered SrTiO 3 substrates by pulsed laser deposition. The high-concentration Zn doping does not suppress the ferroelectric polarization of the BFO films, and the Zn-doped BFO thin films also show reduced leakage current and an enhanced photovoltaic effect. By optical and photoelectron spectroscopy measurements, with Zn doping, the BFO thin films show more oxygen vacancies and a structural evolution, and moreover, a blue-shift of optical bandgap and an increase of work function are demonstrated. The reduction of leakage current and the enhancement of photovoltaic effect are related to the variation of interfacial Schottky junctions and oxygen vacancies with doping. This study reveals systematic insights into the effects of Zn doping on the physical properties of BFO thin films.

Photovoltaic Effect-Based Multifunctional Photodetection and Position Sensing Using a 3C-SiC/Si Heterojunction

“…Depending on the energy sources, different sensing mechanisms can be applied for energy harvesting; for example, piezoelectric, electrostatics, or triboelectric effect for mechanical energy, , thermoelectric for thermal energy, , and photovoltaic effect for light energy. , Among these sensing mechanisms, the photovoltaic effect has demonstrated its superior advantages in harvesting light energy, the most abundant and sustainable energy source. The photovoltaic effect in semiconductive heterojunctions refers to the conversion of photon energy into electrical signals. , Under the illumination of light, electron–hole (e–h) pairs are generated, separated by the heterojunction, and collected by electrodes on two sides of the substrate. This sensing effect has been employed to develop a wide range of photodetectors and solar cells. − For instance, photovoltaic effect-based photodetectors have been applied to different purposes, such as multispectral imaging, biomedical imaging, and advanced optical communication. , …”

“…The photovoltaic effect in semiconductive heterojunctions refers to the conversion of photon energy into electrical signals. 8,9 Under the illumination of light, electron−hole (e−h) pairs are generated, separated by the heterojunction, and collected by electrodes on two sides of the substrate. This sensing effect has been employed to develop a wide range of photodetectors and solar cells.…”