Critical review of recent progress of flexible perovskite solar cells

Solar cells based on emerging organic-inorganic hybrid perovskite materials have reached certified power conversion efficiency as high as 25.5%, showing great potential in the next generation of photovoltaics toward large-scale industrialization. The most competitive feature of perovskite solar cells (PSCs) is that the perovskite light absorber can be fabricated by a low-cost solution method. For the solution method, the characteristics of the solvent play a key role in determining the crystallization kinetics, growth orientation, and optoelectronic properties of the perovskite film. Although significant progress has been made in the field of solvent engineering in PSCs, it is still challenging for the solution method to sustainably produce industrial-scale PSCs for future commercialization applications. Herein, the advanced progress of solvent engineering of precursor solution in terms of coordination regulation and toxicity reduction is highlighted. The physical and chemical characteristics of different solvents in reducing the toxicity of the solvent system, regulating the coordination property of the precursor solution, controlling the film-forming process of the perovskite film, and adjusting the photovoltaic performance of the PSC are systematically discussed. Lastly, important perspectives on solvent engineering of the perovskite precursor solution toward future industrial production of high-performance PSCs are provided.

Solvent Engineering of the Precursor Solution toward Large-Area Production of Perovskite Solar Cells

A Review on Emerging Barrier Materials and Encapsulation Strategies for Flexible Perovskite and Organic Photovoltaics

The perovskite solar cells (PSCs) have emerged as an established technology during the last decade, with the record efficiency of such solar cells having increased from 3.8 % to 25.5 %. Recently, flexible perovskite solar cells (fPSCs) have received much attention from the academic and the industrial communities, owing to their potential for various niche applications, including portable electronics, wearable power sources, electronic textiles, and large-scale industrial roofing. fPSCs are lightweight, bendable, and suitable for roll-to-roll industrial production and can be integrated easily over any surface. This Review discusses the recent development of materials for fPSCs based on various flexible substrates, including plastic, metal, and other flexible substrates, as well as fiber-shaped perovskite solar cells, with a focus on the device structure, material selection for each layer, mechanical flexibility and the environmental stability of the fPSC devices. Finally, future applications and the outlook for fPSCs are also discussed.

Progress in Materials Development for Flexible Perovskite Solar Cells and Future Prospects.

Machine vision is an indispensable part of today's artificial intelligence. The artificial visual systems used in industrial production and domestic daily life rely significantly on cameras and image‐processing components for live monitoring and target identifying. They, however, often suffer from bulky volume, high energy consumption, and more critically, lack of adaptive responsiveness under extreme lighting conditions and thus possible mortal visual disability of flash blinding or nyctalopia for applications such as auto‐piloting. Herein, it is demonstrated that perovskite switchable photovoltaic devices are used to effectively construct all‐in‐one sensory neural network. Arising from the spontaneous and electric field‐induced ion‐migration effect, the photoresponsivity of the perovskite device can be reconfigured over the wide range of 540–1270%, which not only allows high‐fidelity adaptive image sensing of the visual information but also acts as updatable synaptic weight to enable the sensor array for performing machine‐learning tasks. With the bioinspired electronic pupil regulation function achieved through adjustable photoresponsivity of the perovskite sensor array, a proof‐of‐concept adaptive machine vision system with a maximum 263% enhancement of the object recognition accuracy for compact, mobile yet delay‐sensitive applications is demonstrated.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/aisy.202000122

Pei Chun Wang

Papers

Highly flexible, robust, stable and high efficiency perovskite solar cells enabled by van der Waals epitaxy on mica substrate