Flexibility - Page 4

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.

The Emerging PV Reports Initiative (EPVRI) is a new academic international framework for collecting, presenting and analyzing data about the best achievements in the research of emerging photovoltaic materials, e.g., organic, perovskite and dye sensitized solar cells, among others. The new database for collecting, displaying, and analyzing the performance of emerging photovoltaic technologies was spearheaded by researchers in a worldwide international consortium: the Emerging PV Reports initiative.

In order to provide an up-to-date and easy-to-access platform with a global scope, the Emerging PV initiative was established by a consortium of experienced academic researchers from more than 15 countries, all of whom are experts in new and emerging photovoltaic research directions.

Energy Materials Corporation (EMC) has stated its plans for roll-to-roll printing of perovskite PV on glass.

The plan is backed by two partnerships, one with the Eastman Kodak Company for roll-to-roll printing and another with glass and ceramics company Corning, for flexible glass. EMC's funding includes a $4 million research grant from the Solar Energy Technologies Office of the U.S. Department of Energy.

Researchers at South Korea's KRICT, led by Seo Jang-won, have demonstrated pilot-scale "roll-to-roll" (R2R) manufacturing of flexible and light perovskite solar cells.

As an eco-friendly antisolvent, Seo's team introduced tert-butyl alcohol (tBuOH), a colorless solid, which melts near room temperature and has a camphor-like odor, for R2R processing through cooperation with VTT Technical Research Centre of Finland.

A team of researchers at the Ulsan Institute of Science and Technology (UNIST) and Korea University, led by Professors Myung-Hoon Song, Sang-Gyu Kwak and Han-Young Woo, recently announced the development of a PeLED - a perovskite-based LED device, that emits blue light.

The team explained that the perovskite light emitting device, which uses perovskite as a color material, is more than three times more efficient than before and has a high color purity, enabling a clear blue color.

Scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed a new wide-bandgap perovskite layer – called Apex Flex – which they claim is able to withstand heat, light, and operational tests, and at the same time provide a reliable and high voltage.

With this material, they have built tandem solar cells with 23.1% power conversion efficiency on a rigid substrate, and 21.3% on flexible plastic. The new Apex Flex wide-bandgap perovskite recombination layer is grown with atomic layer deposition (ALD). The new material is described as a “nucleation layer consisting of an ultra-thin polymer with nucleophilic hydroxyl and amine functional groups for nucleating a conformal, low-conductivity aluminum zinc oxide layer.”

A team of scientists, led by Professors Hyunsik Im, Hyungsang Kim and Jungwon Kwak from Dongguk University and Asan Medical Center in Korea,have developed perovskite metal halide nanocrystals based hybrid materials with high quantum yields for efficient X-ray detection and high-resolution X-ray imaging.

Using the hybrid nanomaterial scintillators, they designed a scalable and cost-effective X-ray detector panel in liquid form. The hybrid nanomaterial scintillator works under X-ray irradiation typically employed in both diagnosis and treatment. More interestingly, the hybrid scintillator has a faster scintillation decay process over the conventional scintillators, which is beneficial for digital motion X-ray. The reported method and scintillation mechanism will be extended to enhance the quantum yield of various types of scintillators, enabling low-dose radiation detection in various fields including fundamental science and imaging.