Spicy solar cells Easy-grow furniture
Scientists spend a lot of time tinkering with the cells that make up solar panels to increase their efficiency. Perovskite solar cells (PSC) are one type currently being investigated for their promising characteristics, including low production cost and high efficiency. The mineral perovskite was first discovered more than 170 years ago in the Ural Mountains in Russia. It can be used to form the light-harvesting film on solar cells. However, PSCs are relatively unstable and can suffer degradation from light and the environment. They also contain lead, a toxic material. Scientists in China and Sweden have now discovered that a pinch of capsaicin, the chemical compound that makes chilli peppers spicy, can can be used to manufacture more stable and efficient PSCs that have a greater abundance of electrons to conduct current. The team hopes that in the future, the additive can be used with lead-free perovskites to create an efficient, non-toxic solar cell.
Rather than chopping down trees to build furniture, researchers at Massachusetts Institute of Technology (MIT) think they have better idea.
‘If you want a table, then you should just grow a table,’ said Luis Fernando Velásquez-García, principal research scientist at the university. His group has proposed a way to grow certain plant tissues, such as wood, in a lab. The technique is still in its very early stages, but the team has demonstrated the concept by growing structures made of wood-like cells from an initial sample of cells extracted from zinnia leaves.
The cells were cultured in liquid before being transferred to a gel where they were induced to grow a rigid, woodlike structure using a mix of two plant hormones. By varying the levels of these hormones, the team controlled the cells’ production of lignin, the polymer that gives wood its firmness, raising the possibility of a controlled process in which materials optimised for a particular purpose are grown in a lab. ‘The way we get these materials hasn’t changed in centuries and is very inefficient,’ said Velásquez-García. ‘This is a real chance to bypass all that inefficiency.’