Polarization-dependent interfacial coupling modulation of ferroelectric photovoltaic effect in PZT-ZnO heterostructures

Abstract

Recently, ferroelectric perovskite oxides have drawn much attention due to potential applications in the field of solar energy conversion. However, the power conversion efficiency of ferroelectric photovoltaic effect currently reported is far below the expectable value. One of the crucial problems lies in the two back-to-back Schottky barriers, which are formed at the ferroelectric-electrode interfaces and blocking most of photo-generated carriers to reach the outside circuit. Herein, we develop a new approach to enhance the ferroelectric photovoltaic effect by introducing the polarization-dependent interfacial coupling effect. Through inserting a semiconductor ZnO layer with spontaneous polarization into the ferroelectric ITO/PZT/Au film, a p-n junction with strong polarization-dependent interfacial coupling effect is formed. The power conversion efficiency of the heterostructure is improved by nearly two orders of magnitude and the polarization modulation ratio is increased about four times. It is demonstrated that the polarization-dependent interfacial coupling effect can give rise to a great change in band structure of the heterostructure, not only producing an aligned internal electric field but also tuning both depletion layer width and potential barrier height at PZT-ZnO interface. This work provides an efficient way in developing highly efficient ferroelectric-based solar cells and novel optoelectronic memory devices.

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

“…Furthermore, ferroelectric-based PDs have many other attractive properties, such as fast response speed and polarization-dependent adjustable photocurrent. [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.…”

“…These characteristics indicate that ferroelectrics are ideal materials for the fabrication of self‐powered UV PDs. Furthermore, ferroelectric‐based PDs have many other attractive properties, such as fast response speed and polarization‐dependent adjustable photocurrent 14‐16 . Thus, self‐powered UV PDs based on ferroelectric materials have recently attracted increasing interest 17,18 .…”

A One‐Structure‐Based Multieffects Coupled Nanogenerator for Simultaneously Scavenging Thermal, Solar, and Mechanical Energies

“…Similarly, the output voltage reaches a peak value of 0.8 V and then slightly decreases to a stable value of 0.6 V. Maximum output power of 7.6 nW is obtained at a matched loading resistance of 25 MΩ (Figure 2d), suggesting a lower internal resistance of the PVC as compared to the above PENG. Besides, the performance of ferroelectric PVC can be further enhanced by regulating the depolarization field 26, 27. To quantitatively characterize the performance of individual TPiENG, an airflow of 15 m s −1 is generated by a commercial air blower with a distance of 12 cm away from the device.…”

Applications of ferroelectrics in photovoltaic devices

“…To address the interface effect of ferroelectric materials and metal oxide semiconductors, Pan et al [68] added a ZnO layer to the ITO/PZT/Au structure by preparing the samples on commercial ITO-coated glass substrates, using a sol-gel process and spin-coating technique. The performance of these devices was significantly improved compared with that of the original ones.…”