Jülich researchers increase open-circuit voltage of perovskite solar cells
Scientists at Forschungszentrum Jülich have succeeded in increasing the open-circuit voltage of perovskite solar cells to a value of 1.26 V. This value is regarded as the key to improving efficiency.
Perovskit solar cells are regarded as the great hope of photovoltaics. They can be produced cheaply using various printing processes and, after just a few years of research, achieve a similar degree of efficiency in the laboratory as the industrially most commonly used crystalline silicon solar cells. The laboratory efficiency of perovskite solar cells is now over 20 %, while the best silicon solar cells achieve an efficiency of over 26 %.
Until now it was unclear how much the open-circuit voltage of perovskite solar cells could be increased. The highest value so far was 1.21 V. Scientists from the Jülich Institute for Energy and Climate Research (IEK-5) have now shown that the achievable voltage is principally not limited by the contact materials adjacent on both sides. The recombination quality of the layers and interfaces in their cells is similar to that of cells made of silicon and gallium arsenide, which can only be produced using extremely complex methods at high temperatures. With printable photovoltaics and optoelectronics, in the long term similarly efficient optoelectronic components could be realized as with classical semiconductor materials. However, there is still a long way to go before it is ready for application, since the current generation of perovskite solar cells does not yet have sufficient long-term stability.