Hybrids and related materials - Page 6

Oxford Photovoltaics, in collaboration with Helmholtz-Zentrum Berlin (HZB) and the Photovoltaics and Optoelectronics Device Group at the University of Oxford, produced a 1 cm² perovskite-silicon two-terminal tandem solar cell with a verified conversion efficiency of 25.2%. The two-terminal tandem solar cell efficiency was certified by the Fraunhofer Institute for Solar Energy Systems ISE.

Dr Chris Case, Chief Technology Officer at Oxford PV commented, 'The unique, optically enhanced architecture developed as part of this collaboration, minimizes losses, and has helped us achieve this record setting efficiency'.

Oxford PV has announced it has secured a further £8.02 Million (around $11.2 USD) in funding from its existing investors including Statoil and Legal & General Capital, to continue the commercialization of perovskite-on-silicon tandem solar cell technology.

The funding will enable Oxford PV to continue to transfer its advanced perovskite-on-silicon tandem solar cell technology from the company's lab in Oxford, UK to industrial scale processes and equipment at the company's demonstration line in Brandenburg an der Havel, Germany. Oxford PV is working to fully optimize its commercial sized perovskite-on-silicon tandem solar cell technology, to ensure ease of integration into large scale silicon solar cell and module production. The company is closely collaborating with its development partner ' a major manufacturer of silicon solar cells and modules.

The Solar Energy Research Institute of Singapore (SERIS) at the National University of Singapore (NUS) has announced a new R&D goal to develop a commercially viable thin-film-on-silicon tandem solar cell with 30% conversion efficiencies.

SERIS researchers will collaborate with Nanyang Technological University (NTU) and Campus for Research Excellence and Technological Enterprise (CREATE) of NRF on both III-V and perovskite materials, while SERIS will develop optimized silicon bottom cells.

A joint team of researchers led by Professor Federico Rosei at the Institut national de la recherche scientifique (INRS), and Dr. Riad Nechache from École de technologie supérieure (ÉTS), both located in Montreal, Canada, have developed a composite perovskite thin film made of two different inorganic oxide materials that significantly improves the performance of solar cells.

The team demonstrated a cell in which the open-circuit voltage and short-circuit photocurrent are tunable by varying the electrical resistance of the device, which in turn is controlled by externally applying voltage pulses. This provides an alternative way of achieving highly stable, high-efficiency conversion.

Oxford PV recently announced that its perovskite-on-silicon tandem solar cells, currently being used to conduct a life-cycle environmental impact study, have shown positive first results.

The study, commissioned by CHEOPS ' a perovskite research project co-funded by the European research and innovation program Horizon 2020, is being conducted by SmartGreenScans, a CHEOPS member, specializing in Life-Cycle Assessments (LCA) of photovoltaic technologies, to assess the life-cycle environmental impact of the perovskite-on-silicon tandem cells being commercialized by Oxford PV.

A new international study led by chemists at the Georgia Institute of Technology has observed that hybrid organic-inorganic perovskites (HOIPs) possessed a 'richness' of semiconducting physics created by what could be described as electrons "dancing" on wobbling chemical underpinnings. That contradicts established semiconductors that rely upon rigidly stable chemical foundations, or quieter molecular frameworks, to produce the desired quantum properties. This could mean that HOIPs may be used in the future as semiconductors with nuanced colors emanating from lasers, lamps, and even window glass.

HOIPs have been reported by the team to be quite challenging to examine, but the researchers from a total of five research institutes in four countries succeeded in measuring a prototypical HOIP and found its quantum properties on par with those of established, molecularly rigid semiconductors, many of which are graphene-based. 'We don't know yet how it works to have these stable quantum properties in this intense molecular motion,' said first author Felix Thouin, a graduate research assistant at Georgia Tech. 'It defies physics models we have to try to explain it. It's like we need some new physics.'

An international team of researchers led by the University of Cambridge found that a simple potassium solution could boost the efficiency of perovskite-based solar cells, by enabling them to convert more sunlight into electricity. The addition of potassium iodide seems to have a 'healing' effect on the defects and immobilized ion movement, which to date have limited the efficiency of perovskite solar cells.

Tiny defects in the crystalline structure of perovskites, called traps, can cause electrons to get 'stuck' before their energy can be harnessed. The easier it is for electrons to move around in a solar cell material, the more efficient that material will be at converting photons into electricity. Another issue is that ions can move around in the solar cell when illuminated, which can cause a change in the bandgap ' the color of light the material absorbs.

The recent Silicon PV/nPV conference in Lausanne, Switzerland, saw Solliance's announcement on the achievement of a major milestone in perovskite technology for application in future industrial high efficiency tandem photovoltaic cells and modules. Solliance announced realizing a perovskite cell that combines good cell efficiency with a very high near infrared transparency of 93%.

Also at the conference, ECN shows that when this perovskite cell is mechanically stacked on a 6 inch² silicon bottom cell with its proprietary MWT-SHJ (metal-wrap-through silicon heterojunction) design, 26.3% efficiency is achieved, an increase of 3.6% points over the efficiency of the directly illuminated silicon cell laminate.

Researchers at Brown University and University of Nebraska - Lincoln (UNL) have come up with a new titanium-based material for making lead-free, inorganic perovskite solar cells. The team shows that the material has significant potential, especially for making tandem solar cells.

"Titanium is an abundant, robust and biocompatible element that, until now, has been largely overlooked in perovskite research," said the senior author of the new paper. "We showed that it's possible to use titanium-based material to make thin-film perovskites and that the material has favorable properties for solar applications which can be tuned."

Oxford Photovoltaics announced that it was working with scientists at the new Helmholtz-Zentrum Berlin (HZB) innovation lab to further the optimization of its perovskite cell materials for silicon heterojunction solar cell technology.

The new partnership with HZB aims at furthering commercialization efforts with greater leverage of HZB's silicon cell material knowledge and specifically heterojunction cells. 'Working with HZB to understand solar cell manufacturers' silicon cells, will allow Oxford PV's perovskite on silicon tandem formation to be fully optimized, to ensure the most efficient tandem solar cell, and the easy transfer of our technology into our commercial partner's industrial processes", commented Chris Case, Chief Technology Officer, at Oxford PV. 'Oxford PV is now in the final stage of commercializing its perovskite photovoltaic solution, which has the potential to enable efficiency gains that will transform the economics of silicon photovoltaic technology globally.'