Modulating Photovoltaic Conversion Efficiency of BiFeO₃-Based Ferroelectric Films by the Introduction of Electron Transport Layers

Abstract

The sol−gel method exhibits the advantages of simple preparation, low cost, and easy control of stoichiometry, which is widely used for the fabrication of BiFeO 3 -based perovskite ferroelectric films. However, because of the volatilization of organic solvents during the annealing process, voids will inevitably be formed. In this article, high-quality BiFeO 3 -based thin films (with or without La doping) were prepared by physical vapor deposition methods, namely as magnetron sputtering and pulsed laser deposition, respectively. The deposition procedure of gas particles and the annealing process of thin films could be performed simultaneously by pulsed laser deposition, while is impossible by magnetron sputtering. As a result, pulsed laser deposition is considered as a more suitable approach for ferroelectric thin films fabrication. Besides the adoption of the pulsed laser deposition approach for the fabrication of highly dense thin films, the integration of electron transport layers (SnO 2 , TiO 2 , and ZnO) and La 3+ doping is demonstrated to help to alleviate the problem of high electron−hole recombination rate, which then increases the photovoltaic conversion efficiency. In this contribution, planar solar cells, which were fabricated by the pulsed laser deposition approach with TiO 2 as the electron transport layer, exhibited the best efficiency of 5.62% with a reduced leakage current density. This work provides a promising paradigm for the further development of high-performance BiFeO 3 -based perovskite solar cells through the modulation of fabrication process and introduction of electron transport layers.

Large-Scale Epitaxial Growth of Ultralong Stripe BiFeO3 Films and Anisotropic Optical Properties

“…In comparison with the photovoltaic effect in single ferroelectric domain and 71° stripe domains, , we demonstrate a sizable photovoltaic current in pure 109° stripe domains. It is noted that the value and sign of the photovoltaic effect are determined by the dimension of devices (length, width), film thickness, the type of ferroelectric domains (71°, 109°), and the polarization states of domains (under ± voltage poling). , Doping rare-earth metal elements and introducing an electron transport layer to form a heterostructure are effective approaches to modulate photovoltaic conversion . In the future, systematic investigations of the effect of film thickness and domain structures on optical properties should be conducted.…”

Laser Processing Methods for Perovskite Solar Cells and Modules

“…An investigation of La 3+ doping in BiFeO 3 ‐based perovskite ferroelectric films prepared via sputtering and pulsed laser deposition methods was investigated by Zhang et al. [ 64 ] The study looked at the integration of various sol‐gel derived electron transport layers including SnO 2 , TiO 2 , and ZnO, and their influence on the device photovoltaic conversion efficiency. Pulsed laser deposition allowed, in contrast to magnetron sputtering, the simultaneous deposition, and annealing of the films.…”

Progress in lead-free piezoelectric nanofiller materials and related composite nanogenerator devices

“…The increasing popularity of portable electronics and Internet of things (IoT) demands durable and self-maintaining energy sources, intriguing the extensive research on energy conversion devices such as thermoelectric, photovoltaic, piezoelectric devices, and so forth. 23,155,[176][177][178][179][180][181][182][183] According to other mechanical energy harvesting devices, piezoelectric devices relatively did not have critical drawbacks such as weak humidity resistance and related encapsulation difficulty as well as signicant mechanical abrasion problem. 23,[184][185][186] Among them, piezoelectric energy harvesters, which directly convert mechanical energy input into electrical energy output, have been of an intense interest during the last decade for self-powered and ubiquitous applications.…”