Polarization controlled photovoltaic and self-powered photodetector characteristics in Pb-free ferroelectric thin film

Abstract

Ferroelectrics are considered next generation photovoltaic (PV) materials. In this work, a switchable and large PV effect is demonstrated in a Pb-free ferroelectric 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) thin film fabricated by a pulsed laser deposition technique. The material shows a remarkable PV output of 0.81 V due to its morphotropic phase boundary composition. The observed PV effect is analyzed on the basis of the interfacial Schottky barrier and bulk depolarization field. The poling dependent PV studies revealed that although the Schottky and depolarization field contribute to the PV effect, the latter dominates the PV response beyond the coercive field. Additionally, the importance of this compound in the field of a self-biased photodetector is elucidated in terms of calculated photodetector parameters such as responsivity and detectivity. The explored results will bring significant advancement in the field of ferroelectric PV, UV solid state detector applications and also give an additional dimension to the multifunctional ability of the BZT-BCT system.

Depolarization electric field and poling voltage‐modulated Pb,La(Zr,Ti)O3‐based self‐powered ultraviolet photodetectors

“…Figure 5A-E shows the specific detectivities (D*) of the PDs with various Ti contents at different poling voltages. D* reflects the ability of the device to detect weak light signals from noise and can be expressed as Equations (4): 17 As seen from the figures, when the Ti content improves from 40 mol% to 80 mol%, the D* increases to the value of 5.45 × 10 10 Jones at a poling voltage of 2 V, which results from the increase in R λ . However, by further increasing the Ti content, the PDs with 87.5 mol% Ti exhibit a D* value of only 0.89 × 10 10 Jones at the same poling voltage, although it has the largest R λ of 4.17 mA/W, which is attributed to its high dark current (1700 pA).…”

“…[14][15][16] Thus, self-powered UV PDs based on ferroelectric materials have recently attracted increasing interest. 17,18 In recent work, we have confirmed that La-doped Pb(Zr,Ti)O 3 thin film is a promising material for preparing ferroelectric photovoltaic devices due to its high remnant polarization, resulting in efficient separation of the photogenerated electrons and holes. 19,20 This material may render self-powered UV PDs with high photoelectric response performances.…”

Boosting Photocurrent via Heating BiFeO3 Materials for Enhanced Self‐Powered UV Photodetectors

“…The specific detectivity D* presents the ability to detect weak light source signals and reflects the noise in the environment, that is, D* = R/(2e·I d /S) 1/2 , [30] where I d is the value of current in the dark. [9,26] Here, we also demonstrate the value of the largest output powers in Ag/BFO/ITO photodetector by loading different resistances under 365 nm illumination (105.2 mW cm −2 ) at three typical temperatures. The above results indicate that the Ag/BFO/ITO photodetector applies to detect at temperature range around 66.1 °C.…”

“…This may be caused by the temperature-modulated bandgap and barrier height in Ag/BFO/ITO device. [23][24][25][26] As compared with the conventional battery-powered counterparts, the self-powered photodetectors provide advantages of long lifespan and easy integration. above mentioned solar cells, ferroelectric materials, which can exhibit abnormal photovoltaic effect evidencing by above bandgap photovoltage, have attracted much attention.…”

“…[23][24][25][26] As compared with the conventional battery-powered counterparts, the self-powered photodetectors provide advantages of long lifespan and easy integration. [23][24][25][26] As compared with the conventional battery-powered counterparts, the self-powered photodetectors provide advantages of long lifespan and easy integration.…”