Enhanced performance of BiFeO3@nitrogen doped TiO2 core-shell structured nanocomposites: Synergistic effect towards solar cell amplification

A core-shell nano-heterostructured perovskite BiFO3@nitrogen doped mesoporous TiO2 (BFO/n-TiO2) hydrothermally assembled via using citric acid and polyethlene glycol (PEG) was characterized through XRD, TEM, FTIR, UV-Vis diffuse reflectance, IPCE, N-2 adsorption and impedance spectroscopy. It has been demonstrated that the photovoltaic yield of the 90%N-TiO2-10%BFO electrode achieves a power conversion efficiency (PCE) of 4.5%, which is 1.85, 2.5, 3 and 1202 times higher than those of 10%N-TiO2-90%BFO, 50%N-TiO2 -50%BFO, n-TiO2 and pristine BFO, respectively. It is acknowledged that the former electrode exhibits a significant visible light harvesting capability, lowest band gap (E-e = 2.0 eV) as well as the highest IPCE% (36% at 460 nm) values. The EIS and capacitance results illustrated that 90%N-TiO2-10%BFO owns excessive charge carriers (e(-) - h(+)); compared to rest of nanocomposites, with a great sparation, to assist boosting the PCE value. This was highly aided by the surface defects seen on the core represented by BFO, which worked as a rational carrier trapper between the N719 dye and the n-TiO2 shell structure. The surface texturing properties of the nanocomposite forming the 90%N-TiO2-10%BFO electrode including S-BET (Asahi et al., 2001) and pore volume (0.48 cm(-3) g(-1) ) have shared significantly in improving the conversion efficiency of such p-n heterojunction based solar cells; which never achieved as such in all BFO-based solar cell devices, with acceptable tunability. (C) 2018 Production and hosting by Elsevier B.V. on behalf of King Saud University.