Perovskite solar cells surpass 20 percent efficiency

This is a Perovskite solar cell prototype. Image: Alain Herzog / EPFL

EPFL researchers are pushing the limits of perovskite solar cell performance by exploring the best way to grow these crystals.

Michael Graetzel and his team found that, by briefly reducing the pressure while fabricating perovskite crystals, they were able to achieve the highest performance ever measured for larger-size perovskite solar cells, reaching over 20% efficiency and matching the performance of conventional thin-film solar cells of similar sizes. Their results are published in Science.

This is promising news for perovskite technology that is already low cost and under industrial development.

However, high performance in pervoskites does not necessarily herald the doom of silicon-based solar technology. Safety issues still need to be addressed regarding the lead content of current perovskite solar-cell prototypes in addition to determining the stability of actual devices.

Layering perovskites on top of silicon to make hybrid solar panels may actually boost the silicon solar-cell industry. Efficiency could exceed 30%, with the theoretical limit being around 44%. The improved performance would come from harnessing more solar energy: the higher energy light would be absorbed by the perovskite top layer, while lower energy sunlight passing through the perovskite would be absorbed by the silicon layer.

Source
Ecole Polytechnique Fédérale De Lusanne