An international team of researchers, including ones from Brown University, EPFL, Dalian University of Technology and Shaanxi Normal University, has developed a flexible thin-film perovskite solar cell with an efficiency of 21.0%.

The perovskite layer for the cell, which has an “n-i-p” layout, was fabricated using a metal-halide capping layer placed on top of a three-dimensional metal-halide perovskite film. This design reportedly provides hermetically sealed encapsulation, which is traditionally difficult to achieve in flexible perovskite cells, and also enhances the photocarrier properties at the interface between the perovskite film and the hole transport layer (HTL).

Researchers at Duke University have revealed the illusive molecular dynamics that provide halide perovskites with their desirable properties for solar energy and heat energy applications.

A key contributor to how these materials create and transport electricity reportedly stems from the way their atomic lattice twists and turns in a hinge-like fashion. The results could help materials scientists tailor the chemical recipes of these materials for a wide range of applications in an environmentally friendly way.

The U.S. Air Force recently awarded the University of Toledo (UToledo) $12.5 million to develop photovoltaic energy sheets that would live in space and harvest solar energy to transmit power wirelessly to Earth-based receivers or to other orbital or aerial instrumentation, such as communications satellites.

UToledo physicists will develop flexible solar cell sheets, each roughly the size of a piece of paper, that can be assembled and interconnected into much larger structures. The team will focus on tandem architectures and work with a variety of combinations of solar cells, perovskites included.

Scientists from South Korea have developed a foldable thin-film device with promising characteristics. Integrating a perovskite cell material and a carbon nanotube electrode, the group fabricated a device that achieved 15.2% efficiency and could be folded more than 10,000 times at a bending radius of 0.5mm.

Solar cell materials tend to be quite sensitive. Designing and manufacturing devices that can withstand the stress of being folded and bent is challenging, and many of even the most promising solutions are still quite limited in their flexibility. The scientists at Pusan National University in South Korea took a major step forward in solving this problem, fabricating a device that can be folded down to a 'bending radius' ' the minimum size of fold possible without causing damage ' of 0.5mm.

Power Roll, a developer of low-cost and lightweight flexible film for energy generation and storage, recently reported raising £3 million (around USD$4.16 million), which joins a previous raise and takes total investment in the firm to £5.8 million (over USD$8 million) over two funding rounds completed in the last six months.

Power Roll is working with a perovskite solar ink, and has already achieved 11% efficiency, with a roadmap to bring this to 20%. Power Roll also states that its substrate is compatible with any photo absorbing ink.

Solliance and U.S-based MiaSolé announced a new record - power conversion efficiency of 26.5% on a tandem solar cell that combined a top rigid semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.

This impressive efficiency was achieved by optimizing the bandgap and the efficiency of both the rigid semi-transparent perovskite top cell and the flexible CIGS bottom cell. The CIGS was roll to roll produced on steel foil, with a power conversion efficiency of 20.0%.

A multi-institution team of researchers, led by the Davidson School of Chemical Engineering at Purdue University, has reported a breakthrough in the flexible solar cell field that may contribute to the development of solar cells on flexible surfaces, including ultra-flexible and wearable energy-harvesting devices.

'Our research is unique in that we have created the first mechanically self-healing perovskite material,' says Blake Finkenauer, lead author of the study and a fourth-year graduate student with Dr. Letian Dou, the Charles Davidson Assistant Professor of Chemical Engineering at Purdue. 'Self-healing mechanical damage has only been realized in the organic materials field, typically with insulating materials. By joining dissimilar perovskite and polymer materials, a composite material with both semiconducting and self-healing properties is realized. The polymer acts as a molecular bonding agent with the crystals, which improves both the thermal and mechanical stability compared to the pure perovskite material".

Energy Materials Corporation (EMC), developer of high-speed roll-to-roll manufacturing of solar energy panels, recently announced that it has developed an enabling process to print transparent conductors as part of the scale-up of its inline manufacturing process.

Roll-to-roll printing of metal conductors on Corning Willow Glass (flexible glass) at 60 meters per minute reportedly sets a world speed record for printing flexible electronics on glass. The process surpasses the company's goal of achieving less than 5% loss in the transmission of light though the conductive layer.

Venture Kick, a private consortium that aims to push forward young entrepreneurs with high-potential business ideas, has selected Perovskia, a nascent perovskite-based solar cells company, to receive CHF40,000 (around USD$45,170).

Perovskia is a young startup that has developed a digital printing technology to fabricate efficient and stable perovskite solar cells with custom design capability. The fabrication techniques they developed are reportedly highly efficient and flexible, which could reduce the production cost considerably, even for customized items. The team plans to use its technology to cater to the diverse needs of Internet of Things, electronic goods, sensors, and ultimately designer solar tiles industries.

Researchers at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University have used the lab's X-ray laser to watch and directly measure the formation of polarons for the first time. Polarons are fleeting distortions in a material's atomic lattice that form around a moving electron in a few trillionths of a second, then quickly disappear. Despite their transient nature, they do affect a material's behavior, and may even be the reason that solar cells made with lead hybrid perovskites achieve extraordinarily high efficiencies in the lab.

Polaron 'bubbles' of distortion form around charge carriers ' electrons and holes that have been liberated by pulses of light ' which are shown as bright spots here. Image by SLAC

Perovskite materials are famously complex and hard to understand, according to Aaron Lindenberg, an investigator with the Stanford Institute for Materials and Energy Sciences (SIMES) at SLAC and associate professor at Stanford who led the research. While scientists find them exciting because they are both efficient and easy to make, raising the possibility that they could make solar cells cheaper than today's silicon cells, they are also highly unstable, break down when exposed to air and contain lead that has to be kept out of the environment.