Perovskite chemistry research to inspire better solar cells

Scientists at the Stanford Synchrotron Radiation Lightsource (SSRL) and Stanford University have found a way to make perovskites with qualities ideal for the material's use in solar cells. "Our study builds on work by other groups of researchers at Oxford, Cornell and Stanford that showed using chlorine in the processing can lead to high-quality perovskite films with impressive performance," Aryeh Gold-Parker, PhD student in Stanford University's chemistry department, said.

The perovskite production process begins by dissolving the basic ingredients in a solvent. The solution is deposited and dried, creating a film. The initial crystallized film is known as the precursor. Finally, the film is heated and cooled, reorganizing the film's structure and yielding a perovskite. Though the basic recipe and ingredients are simple, slight chemical manipulations at each stage of the production process can alter the material's physical properties.

CIGS/perovskite solar cell by UCLA reaches 22.4% efficiency

UCLA researchers have recently reported a highly efficient thin-film solar cell with a double-layer design that converts 22.4% of the incoming energy from the sun. The device is made by spraying a thin layer of perovskite onto a commercially available solar cell. The solar cell that forms the bottom layer of the device is made of a compound of copper, indium, gallium and selenide, or CIGS.

The performance was reportedly confirmed in independent tests at the U.S. Department of Energy’s National Renewable Energy Laboratory. The UCLA device’s efficiency rate is similar to that of the poly-silicon solar cells that currently dominate the photovoltaics market.

Oxford PV receives a €2.8 million grant to prepare perovskite-silicon solar cell production for high volume manufacture

Oxford Photovoltaics (PV) has been awarded a €2.8 million grant from the German Ministry of Economic Affairs and Energy to prepare perovskite-silicon solar cells for high-volume manufacturing. The technology consortium is by headed by Oxford PV and includes specialist PV equipment manufacturer VON ARDENNE and three German institutes, Fraunhofer Institute for Solar Energy Systems, Helmholtz-Zentrum Berlin (HZB) and the Technical University of Berlin.

The newly funded project focuses on the optimization of the perovskite-silicon tandem solar cell architecture, to make further efficiency improvements on industrial 156 mm x 156 mm wafer formats. Importantly, this will include the refinement of industrial scale process technology as well as life-cycle analysis on the social-environmental impact of such cells.

New configuration may offer highly improved efficiency

Researchers from Lahore University and Benha University have proposed an interesting configuration of combination of solar materials that can possibly boost total electricity output by 10-30% – reportedly reaching between 30-36% efficiency.

The proposed solar configuration image(a)bifacial per/Si double-tandem cell (b)standalone bifacial single-tandem cell (c)PVK cell (d)Si heterojunction with intrinsic thin layer solar cell

The researchers describe the cell: "a 3-T, four-junction perovskite/silicon double-tandem (PSDT) solar cell structure that can efficiently harvest light in all ranges of albedo by stacking two tandem perovskite/silicon cells in a flipped configuration with a common (middle) terminal".

Researchers design a method to reversibly adjust the emission color of perovskite nanoparticles

Researchers from ITMO University, along with colleagues from Sweden, Australia, the United States and Lithuania, have discovered Fano resonance in perovskite nanoparticles and gained control over the resonance spectrum for an array of inorganic nanoparticles. This newly designed method reversibly adjusts the radiation color of nanosized light sources. Previously, radiation color could be specified only during nanoparticle synthesis, but now it can be changed after synthesis. Stability and electromagnetic resonances of the particles are retained during this adjustment. This makes them promising for optical chips, LEDs and optoelectronic devices.

Researchers design a method to reversibly adjust the emission color of perovskite nanoparticles image

Resonance is the coincidence between frequencies of two oscillations increasing their intensity. A half-century ago, the Italian theoretical physicist Hugo Fano described a special type of resonance with an asymmetric profile arising from the interference of two wave processes. Since then, Fano resonance has been actively used in photonics, for example, to create fast optical switches. The reduction of such switches to nanoscale will dramatically increase the performance of photonic chips by integrating a huge number of elements in one device.

Researchers calculate that a 32% perovskite/silicon tandem cell solar will still be competitive at triple the price

Researchers from Arizona State University’s Fulton Schools of Engineering have calculated that a 32% efficient perovskite-silicon tandem cell could produce electricity at the same price as cutting-edge 22% efficient panels in the most cost-competitive of situations.

ASU team finds that a 32% tandem cell solar still competitive at triple the price

The paper specifies: “…a large cost benefit will not necessarily be needed to prefer tandem systems over single-junction systems, because higher efficiencies bring additional perceived benefits such as reduced installation area. It is, however, necessary that the path leading to such a tandem be continuously profitable.”

German scientists track perovskite defects to increase efficiency

A team of researchers from the University of Potsdam and HZB has identified loss processes in perovskite solar cells that limit their efficiency, and found that the most significant efficiency losses occur at the interface between the perovskite and transport layer.

SOLAR German scientists observe perovskite defects to increase cell efficiencies image

In certain defects in the crystal lattice of the perovskite layer, charge carriers (i.e. electrons and "holes") that have been released by sunlight can recombine again and thus be lost. But whether these defects were located within the perovskite layer or at the interface between the perovskite layer and the transport layer was unclear until now.