Enhancing Photovoltaic and Photosensing Performances in Bismuth Ferrite via Polar Order Engineering

Abstract

Recent emerging developments have demonstrated that bismuth ferrite is one of the promising lead-free perovskite materials used in solar energy harvesting devices and photodetectors. This work reports high short-circuit photocurrent densities of ∼1.2 × 10 3 and ∼0.55 × 10 3 μA/cm 2 in a p-type gadolinium-doped BiFeO 3 ceramic with n-type indium tin oxide under 405 nm irradiation and sunlight at 10 2 mW/cm 2 intensity, respectively. Polarization-enhanced photoresponsivity of ∼5.4 × 10 −2 A/W and specific detectivity of ∼1.5 × 10 11 Jones were achieved with response times of ∼1 and ∼10 ms, respectively, at the rising and decaying edges. Enhanced photovoltaic conversion via a prior electric-field poling can be attributed to the p−n junction and the field-modulated Schottky barrier in conjunction with domain nucleation, ordered polar nanoregions, and increased O 2p−Fe 3d orbital hybridization. The network of domain walls and grain boundaries serves as conduction pathways for the photogenerated charge carriers. The improved photocurrent in gadolinium-doped BiFeO 3 opens up an opportunity for using bismuth ferrite materials in self-powered photodetectors. KEYWORDS: (Bi 0.93 Gd 0.07 )FeO 3 , photocurrent, photoresponsivity, photoresponse time, domain wall

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

“…Moreover, to obtain more information about the photovoltaic effects, the J sc , V oc , power conversion efficiency (PCE), and external quantum efficiency (EQE) at different light intensities have been measured and are shown in Figures S2–S5. A comparison of the photovoltaic performance of our BFZO films with the reported BFO-based materials − is presented in Table S2.…”

“…UPS spectra and spectroscopic ellipsometry can be utilized to estimate the energy band diagrams of oxide materials. ,, To investigate the effect of Zn doping on the work function and energy band of the BFZO thin films, UPS spectra and absorption spectra have been obtained for the thin films. Figure shows the UPS spectra for the BFZO thin films measured with an He I source (21.22 eV).…”

Spray pyrolysis-derived robust ferroelectric BiFeO3 thin films

“…The estimated crystallite size using the strain size plot method is in the range of 16–23 nm, and comparable to the reported results. 15,16,22,23 The slight disparity in the calculated crystallite size values between the two methods arises due to their different assumptions related to strain. Scherrer's method does not consider strain contributions, whereas the strain size plot method does.…”

Self-Powered Bipolar Photodetector Based on a Ce-BaTiO3 PTCR Semiconductor for Logic Gates

“…In fact, the complex photovoltaic process in ferroelectrics involves more than one mechanism. In general, the built-in electric field induced by a Schottky barrier at the electrode/ferroelectric interface, and the depolarization field over the whole bulk may corporately contribute to the photocurrent in ferroelectric devices. − However, there is a competition between the two effects, and the question of which one plays the dominant role depends on the configurations of the ferroelectric devices, such as body material, thickness, electrode, etc. − …”