perovskite tagged posts

Stanford engineers created arrays of silicon nanocones to trap sunlight and improve the performance of solar cells made of bismuth vanadate (1μm=1,000 nanometers). Credit: Wei Chen and Yongcai Qiu, Stanford

A Stanford University lab has developed new technologies to tackle 2 of the world’s large energy challenges: clean fuel for transportation and grid-scale energy storage. Although H-cars are emission-free, making hydrogen fuel, however, is not emission free: today, making most H fuel involves natural gas in a process releasing CO2 into the atmosphere.

To address the problem, Cui and his colleagues have focused on photovoltaic water splitting which consists of a solar-powered electrode immersed in water...

The perovskite film (black, 200-300 nm) is covered by Spiro.OMeTAD, Graphene with gold contact at one edge, a glass substrate and an amorphous/crystalline silicon solar cell. Credit: F. Lang / HZB

Measurements show the graphene layer is an ideal front contact in several respects. Silicon absorbers primarily convert the red portion of the solar spectrum very effectively into electrical energy, whereas the blue portions are partially lost as heat. To reduce this loss, the silicon cell can be combined with an additional solar cell that primarily converts the blue portions.

Teams at HZB have already acquired extensive experience with these kinds of tandem cells. A particularly effective complement to conventional silicon is the hybrid material called perovskite. It has a band gap of 1...