Ultrathin and lightweight organic solar cells with high flexibility

TLDR

Organic solar cells are promising for lightweight, mechanically robust applications such as lighting, displays, electronic skin, textiles, and surface‑conforming foils, where large‑area, low‑weight, and resilient devices are required. The study aims to develop flexible organic solar cells thinner than 2 µm with very low specific weight that retain photovoltaic performance under repeated mechanical deformation. The authors create a random network of folds within the device area instead of a single bend to achieve flexibility. They demonstrate polymer‑based photovoltaic devices on plastic foils thinner than 2 µm that match glass‑based efficiencies, withstand extreme reversible deformation, exhibit unprecedented low specific weight, and are more than ten times thinner, lighter, and flexible than any other solar cell technology, with standard processing enabling similar benefits for LEDs, capacitors, and transistors.

Abstract

Application-specific requirements for future lighting, displays and photovoltaics will include large-area, low-weight and mechanical resilience for dual-purpose uses such as electronic skin, textiles and surface conforming foils. Here we demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2 μm thick, with equal power conversion efficiency to their glass-based counterparts. They can reversibly withstand extreme mechanical deformation and have unprecedented solar cell-specific weight. Instead of a single bend, we form a random network of folds within the device area. The processing methods are standard, so the same weight and flexibility should be achievable in light emitting diodes, capacitors and transistors to fully realize ultrathin organic electronics. These ultrathin organic solar cells are over ten times thinner, lighter and more flexible than any other solar cell of any technology to date. Organic solar cells are promising for technological applications, as they are lightweight and mechanically robust. This study presents flexible organic solar cells that are less than 2 μm thick, have very low specific weight and maintain their photovoltaic performance under repeated mechanical deformation.