Researchers at the Qatar Environment and Energy Research Institute worked alongside colleagues at Trinity College Dublin to solve solar energy mysteries related to the physical properties of photovoltaic perovskite materials. Their discovery may lead to more efficient solar energy harvesting.

Carlo Motta, Fedwa El-Mellouhi, Sabre Kais, Nouar Tabet, Fahhad Alharbi and Stefano Sanvito (acting director of the Irish funded AMBER material’s science centre) published their research in the prestigious journal Nature Communications.

Their paper, entitled: Revealing the role of organic cations in hybrid halide perovskite CH₃NH₃PbI₃ explains how the organic molecules and inorganic salts in perovskites work together to achieve 20% or better photovoltaic harvesting efficiency.

Persovkites were known to be particularly efficient in converting solar energy into electricity but no one knew why, until now. To understand this research, it helps to know that from the 1950s when Bell Labs began producing photovoltaics for the US space program until now, most commercial photovoltaics rely on the semiconductor properties of doped silicon. “Dope” (impurities) in the silicon crystal lattice is added to favour the capture of photons, creation of electrons/holes pairs and help maintain charge separation.

These are at least three important characteristics of efficient photovoltaic (PV) materials: The first is that it must capture photons. The reason most PV materials appear black or dark-blue is that they are efficient at capturing (not reflecting) photons of many wavelengths.

The second characteristic is that it is able to convert the energy of photons into electron/hole pairs. When a photon’s energy knocks an electron out of its comfortable position within the crystal, it leaves a hole and the photon’s energy is converted into a tiny separation of charge (voltage.)

The third important characteristic of an efficient PV material is the ability to preserve charge separation so the majority of electrons don’t fall back into holes before exiting via conductive electrodes. Ideally the atoms and molecules of a PV material would be shaped as one-way valves, allowing light to bump electrons out of their holes while keeping them from falling back.

Using computational models, the Qatari and Irish scientists were able to simulate the behaviour of  persovkites and determine that at the molecular level, the inorganic molecule shapes change the band gap voltage in such a way that favours photon capture and the creation of electron/hole pairs while slowing the process of electrons falling back into holes. The understanding gained from this approach will allow people to develop even more efficient solar energy capture materials.

Image of sun catcher from Shutterstock

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Some projects that cross my desk are blatantly not as “green” as their investors want us to believe, yet have many redeeming qualities. Take Al Hamra Real Estate’s breakout mega-development, Falcon Island. It’s slated for construction in Ras-al-Khaimah, the emirate north of Dubai, and it’s going gangbusters with solar energy.

Picked to work on this most bespoke island development, international architecture studio A++ is going all out to make sure it keeps pace with some of the most rigorous environmental standards. Relatively speaking, of course, given the multimillion dollar price tag.

Falcon Island will comprise 150 luxurious villas and 11 mansions, which will be equipped with state-of-the-art energy systems – both generating systems and smart systems that maximize energy efficiency. And we expect they’ll be extravagantly decked out inside as well, given this statement on the press release.

“Through exclusive partnerships with interior design group, Luxury Living, and home furnishing brands Bentley Home, Fendi Casa, and Kenzo Maison, each of the villas will combine sustainable technologies with quality craftsmanship.”

It is unabashedly over the top, yet it has a green conscience. Which might be more like a sense of survival, because anyone who is paying attention knows that going off grid is the way of the future. Not only will the bridge entering the island have a solar roof, but the villas will also have rooftop panels.

Related: Massive solar factory opens in Qatar

This accumulated solar energy won’t only provide enough energy for lighting and electricity, but it will also be used to power an on-site desalination plant, street lights, and possibly a solar-powered cooling system.

“The whole complex will be characterized by the implementation of high sustainability systems , both for the production of electricity as well as for the production of thermal energy,” writes A++.

“The villas will be built using a partial pre-cast assembly, performed by dedicated companies in protected environment thereby ensuring effective control of the quality of the implementation, [and] the villas will be characterized by the use of sustainable materials and technical systems with low consumption and low maintenance.”

Which is to say, A++ appears to be super committed to making this an awesome testing ground for advanced technology, which is a great idea.

Though we really aren’t comfortable with the notion that only a privileged group, a group that can afford more than USD 3 million for a waterfront mansion, can have access to this kind of self-sufficiency, we don’t mind using them as guinea pigs for some new ideas.

And then hopefully in time the technology will become more scalable for a wider audience.

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