August 2018

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.

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.

(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 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.

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 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.

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.'

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.

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.