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Inserting a metal fluoride layer in multilayered perovskite-silicon tandem solar cells can stall charge recombination and enhance performance, KAUST researchers have found.

Tandem solar cells that combine and silicon-based subcells in one device are expected to better capture and convert sunlight into electricity than their conventional single-junction silicon analogs at a lower cost. However, when strikes the perovskite subcell, the resulting pairs of electrons and positively charged holes tend to recombine at the interface between perovskite and the electron-transport layer. Also, a mismatch between energy levels at this interface hinders electron separation within the cell. Cumulatively, these problems lower the maximum operating voltage available, or open-circuit voltage, of the tandem cells and limit device performance.

These performance issues can partially be solved by introducing a lithium fluoride layer between the perovskite and electron-transport layer, which usually comprises the electron-acceptor fullerene (C60). However, lithium salts readily liquify and diffuse through surfaces, which makes the devices unstable. “None of the devices have passed the standard test protocols of the International Electrotechnical Commission, prompting us to create an alternative,” says lead author Jiang Liu, a postdoc in Stefaan De Wolf’s group.

A fter schools shifted to an online teaching mode, 17-year-old Nisha Pathak was worried about her increase in screen time. To avoid spending too much time looking at computers and to keep herself active, the Class 12 student of Neeraja Modi school, Jaipur, Rajasthan, took up farming.

“I wanted to keep myself engaged in activities that did not require looking at a screen. Apart from that, I wanted to grow the veggies and distribute them to underprivileged families living near my home,” says Nisha, adding that she learnt how to prepare seeds and plant them from a gardener in her community premises.

Initially, she grew vegetables like potatoes, onions and tomatoes. The harvest was distributed among underprivileged families who were living in neighbouring areas and were unable to procure fresh vegetables regularly.

The Virus Zoo is my latest educational blog post! I’ve written up ~1 page ‘cheat sheets’ on the molecular biology of specific viruses. I cover genome, structure, and life cycle. So far, my zoo includes adeno-associated virus (AAV), adenovirus, and herpes simplex virus 1 (HSV-1). However, I plan to add more viruses as time goes on! Some others I would like to incorporate later are coronavirus, HIV, anellovirus, lentivirus, ebolavirus, and MS2 bacteriophage. Feel free to suggest other interesting viruses in the comments! All images were created by me. #virology #molecularbiology #biotechnology #genetherapy #virus #biochemistry #genetics


Genome and Structure:

AAV genomes are about 4.7 kb in length and are composed of ssDNA. Inverted terminal repeats (ITRs) form hairpin structures at ends of the genome. These ITR structures are important for AAV genomic packaging and replication. Rep genes (encoded via overlapping reading frames) include Rep78, Rep68, Rep52, Rep40.1 These proteins facilitate replication of the viral genome. As a Dependoparvovirus, additional helper functions from adenovirus (or certain other viruses) are needed for AAVs to replicate.

AAV capsids are about 25 nm in diameter. Cap genes include VP1, VP2, VP3 and are transcribed from overlapping reading frames.2 The VP3 protein is the smallest capsid protein. The VP2 protein is the same as VP3 except that it includes an N-terminal extension with a nuclear localization sequence. The VP1 protein is the same as VP2 except that it includes a further N-terminal extension encoding a phospholipase A2 (PLA2) that facilitates endosomal escape during infection. In the AAV capsid, VP1, VP2, and VP3 are present at a ratio of roughly 1:1:10. It should be noted that this ratio is actually the average of a distribution, not a fixed number.

Solar energy and onshore wind are crucial to unlocking Africa’s hydrogen potential, the International Energy Agency (IEA) said in its Africa Energy Outlook 2022. “With further cost declines, Africa has the potential to produce 5 000 megatonnes of hydrogen per year at less than $2 per kilogram,” reads the report. The continent has 60% of the world’s best solar resources, but only 1% of its operational solar generation capacity.

Serbia and Hungary signed a memorandum of understanding to collaborate on renewable hydrogen. “The signed memorandum is the basis for exchanging documents in this area and discussing potential joint projects,” said the Serbian government.

Nuclear fusion promises practically limitless energy and an unshackling from the harmful impact of fossil fuel consumption.

Now, researchers from the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) announced they found a way to build powerful magnets much smaller than ever before, a press statement reveals.

Interesting Engineering.


A group of researchers from Princeton Plasma Physics Laboratory found a way to build powerful magnets much smaller than ever before.