Abstract
Self-powered photodetection was studied using x wt% ZnO-modified (Bi0.93Gd0.07)FeO3 (abbreviated as B7GFO-xZn) ferroelectric ceramics. The ITO/B7GFO-xZn ceramic/Au photovoltaic (PV) cell was constructed for photosensing study at ultraviolet-A (λ = 360 nm) and near-ultraviolet (λ = 405 nm). The +2kV/cm poled PV cell using B7GFO-1 wt%Zn ceramic under 360-nm irradiation displays maximal photocurrent density of ~364 μA/cm2 at 102 mW/cm2. Furthermore, a remarkable photosensing performance was observed with photoresponsivity (R) of ~3.02×10?2A/W, specific detectivity (D*) of ~2.27×1012 Jones, and photoconductive gain (G) of ~10.4%. A sensitive photosensing response time (rise time, τr) of ~9 ms was acquired under illumination from the 360-nm laser at 102 mW/cm2. The enhanced photodetection performance originated from the collective influence of the narrower bandgap, enhanced p-n junction effect, E-field-modulated energy band tilt, and improved photocurrent generation due to the local conductive pathways formed by the interconnected domain walls and grain boundaries. This work provides an extensive analysis to elucidate the photovoltaic mechanisms in BiFeO3-based ceramics and explores their potential in self-powered UV photosensing.
NSTL
Elsevier