Pushing the Limits of Flexibility and Stretchability of Solar Cells: A Review

Abstract

Emerging forms of soft, flexible, and stretchable electronics promise to revolutionize the electronics industries of the future offering radically new products that combine multiple functionalities, including power generation, with arbitrary form factor. For example, skin‐like electronics promise to transform the human‐machine‐interface, but the softness of the skin is incompatible with traditional electronic components. To address this issue, new strategies toward soft and wearable electronic systems are currently being pursued, which also include stretchable photovoltaics as self‐powering systems for use in autonomous and stretchable electronics of the future. Here recent developments in the field of stretchable photovoltaics are reviewed and their potential for various emerging applications are examined. Emphasis is placed on the different strategies to induce stretchability including extrinsic and intrinsic approaches. In the former case, engineering and patterning of the materials and devices are key elements while intrinsically stretchable systems rely on mechanically compliant materials such as elastomers and organic conjugated polymers. The result is a review article that provides a comprehensive summary of the progress to date in the field of stretchable solar cells from the nanoscale to macroscopic functional devices. The article is concluded by discussing the emerging trends and future developments.

Recent Progress on Emerging Transparent Metallic Electrodes for Flexible Organic and Perovskite Photovoltaics

“…It should be noted that all materials are bendable to some extent, while the exact extent of bending depends on both the material Young's modulus and its geometry (thickness). [137,139] As a cyclic (or repetitive) bending loading system is easier to apply on the substrate, most of the surveyed literature employs the alternating bending loading of Figure 4c to characterize the flexibility of solar cells. The alternating bending test is indexed by a curvature radius R (as shown in Figure 4d).…”

“…While silicon‐based photovoltaics dominates the commercial market, the covalence bonds in silicon results in most commercial silicon‐based devices being intrinsically rigid. [ 137 ] Although flexibility in silicon‐based electronics can be enabled extrinsically by preparing wavy or buckling stretchable silicon structures, [ 138 ] organic materials and composites stand to much better fulfill the role of flexible photovoltaics, as many are intrinsically soft or flexible. Hence, in this section, focus will be given to two promising flexible solar cell technologies based on thin‐film organic or organometallic materials, that is, OSCs and PSCs).…”

Effects of Regioregularity of π‐Conjugated Polymers Composed of Boron β‐Diketiminate on Their Stimuli‐Responsive Luminescence

“…𝜋-Conjugated polymers have attracted considerable attention from both academic and industrial researches because of their promising applicability to next-generation optoelectronic devices such as organic light-emitting diodes, [1][2][3] photovoltaic cells, [4][5][6] organic field-effect transistors, [7] and chemical and biological sensors. [8] Considering their applications in the solid states, material properties should be governed not only by first-order structures composed of 𝜋-conjugated backbones but by higher-order structures involving solid-state morphology.…”

Phenalene—A New Ring-Locked Vinyl Bridge for Nonfullerene Acceptors With Enhanced Chemical and Photochemical Stabilities

“…As one of the third-generation photovoltaic techniques, organic solar cells (OSCs) have demonstrated outstanding potentials in the fields of flexible devices, semi-transparent devices, indoor photovoltaics, and so on (Liu et al, 2021c;Dauzon et al, 2021;Kini et al, 2021;Xie et al, 2021). Excitingly, the record power conversion efficiency (PCE) of OSCs has been continuously rising in recent years, and a value exceeding 19% has been achieved already Wang et al, 2021), attributed to the innovative design and exploitation of photovoltaic materials and device architecture (Li et al, 2019;Cui and Li, 2021;Liu W. et al, 2021;Gao et al, 2021;Ren et al, 2021;Yin et al, 2021;Zheng et al, 2021).…”