An insight into the analogies, state-of-the-art technologies, concepts, and prospects under the umbrella of perovskite materials (both inorganicorganic hybrid halide perovskites and ferroelectric perovskites) for future multifunctional energy conversion and storage devices is provided. Often, these are considered entirely different branches of research; however, considering them simultaneously and holistically can provide several new opportunities. Recent advancements have highlighted the potential of hybrid perovskites for high-efficiency solar cells. The intrinsic polar properties of these materials, including the potential for ferroelectricity, provide additional possibilities for simultaneously exploiting several energy conversion mechanisms such as the piezoelectric, pyroelectric, and thermoelectric effect and electrical energy storage. The presence of these phenomena can support the performance of perovskite solar cells. The energy conversion using these effects (piezo-, pyro-, and thermoelectric effect) can also be enhanced by a change in the light intensity. Thus, there lies a range of possibilities for tuning the structural, electronic, optical, and magnetic properties of perovskites to simultaneously harvest energy using more than one mechanism to realize an improved efficiency. This requires a basic understanding of concepts, mechanisms, corresponding material properties, and the underlying physics involved with these effects. His current research focuses on developing functional inorganic−organic hybrid materials and energy conversion devices including perovskite solar cells.are found to have lower t-values (0.75 < t < 1.0). t-values help in governing and tuning the presence of ferroelectricity in perovskites [11] and are responsible for the transition temperatures in ferroelectrics. [57] In the case of hybrid inorganic-organic perovskites, the A-site and/or X-site ions are replaced by molecular building blocks; hence, the tolerance

Photo‐ferroelectric single crystals and highly oriented thin‐films have been extensively researched recently, with increasing photovoltaic energy conversion efficiency (from 0.5% up to 8.1%) achieved. Rare attention has been paid to polycrystalline ceramics, potentially due to their negligible efficiency. However, ceramics offer simple and cost‐effective fabrication routes and stable performance compared to single crystals and thin‐films. Therefore, a significantly increased efficiency of photo‐ferroelectric ceramics contributes toward widened application areas for photo‐ferroelectrics, e.g., multisource energy harvesting. Here, all‐optical domain control under illumination, visible‐range light‐tunable photodiode/transistor phenomena and optoelectrically tunable photovoltaic properties are demonstrated, using a recently discovered photo‐ferroelectric ceramic (K0.49Na0.49Ba0.02)(Nb0.99Ni0.01)O2.995. For this monolithic material, tuning of the electric conductivity independent of the ferroelectricity is achieved, which previously could only be achieved in organic phase‐separate blends. Guided by these discoveries, a boost of five orders of magnitude in the photovoltaic output power and energy conversion efficiency is achieved via optical and electrical control of ferroelectric domains in an energy‐harvesting circuit. These results provide a potentially supplementary approach and knowledge for other photo‐ferroelectrics to further boost their efficiency for energy‐efficient circuitry designs and enable the development of a wide range of optoelectronic devices.

This work examines the potential of PbZr 0.53 Ti 0.47 O 3 /CoFe 2 O 4 (PZT/CFO) multi-layered nanostructures (MLNs) for giant electrocaloric effect (ECE) and pyroelectric energy harvesting.Unlike the conventional ECE, the presented MLNs is governed by the dynamic magneto-electric coupling (MEC) and can be tuned by the arrangement of the various ferroic layers. The ECE in alternate layers of PZT and CFO in a stack of three (L3), five (L5) and nine (L9) alternating PZT and CFO layers are investigated. An ECE temperature change of 52.3 K, 32.4 K and 25.0? K is predicted in these MLNs respectively. Intriguingly, all configurations exhibit a negative ECE which has a high magnitude in comparison with previously reported giant negative ECE (|∆T|=6.2 K) 1, 2 . In addition, the maximum indirect pyroelectric energy harvesting obtained from these layers using a modified Olsen cycle is four times higher than the highest reported pyroelectric energy density of 11549 kJm -3 cycle -1 3, 4 . This increase is attributed to the cumulative effect of multiple layers that induce an enhancement in the overall polarization (1.5 times of lead zirconate titanate) and leads to abrupt polarization changes with a temperature fluctuation. The present study also sheds light on materials selection and the thermodynamic processes involved in the ECE. It is concluded that the refrigeration obtained from reversed Olsen cycle is a combined effect of an isothermal entropy as well as adiabatic temperature change.