The certified power conversion efficiency (PCE) of organic-inorganic hybrid perovskite solar cells can exceed 25.5% currently. However, stability remains the dominating obstacle in practical applications as it’s easy to degrade when exposed in the air. Scientists have been trying to make the device stable, better with self-healing properties that can resist hostile operation environments.
Recently, perovskite solar cell with self-healing effect via functional incorporation of polyvinylpyrrolidone was developed by a team led by Prof. HU Linhua from Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences.
"Air moisture is the key issue for perovskites. It invades the films and accelerates the damage of devices." said Prof. HU, "That's why we introduce polyvinylpyrrolidone (PVP) to the methylammonium lead iodide (MAPbI3) perovskite precursor. It can control crystal growth and endow the devices with self-healing ability in a moisture environment."
PVP is a polymer with many carbonyl groups. After introducing PVP in perovskite solar cell, it works as a "protective armour with automatic blood return effect" against water vapor. Moreover, PVP can improve the crystal growth with fewer defects and large grains.
Perovskite solar cells are considered as competitive alternatives for conventional silicon solar cells. The tandem solar cell between perovskite solar cell and silicon solar cell reached have gained a certified efficiency of more than 29% till now. The tandem technology is believed as development tendency in the future.
This work was supported by the National Key Research and Development Program of China (2017YFE0133800), the National Natural Science Foundation of China (51961165106), the West Light Foundation of the Chinese Academy of Sciences (XAB2020YW11), and European Union’s HORIZON 2020 Marie Curie Innovative Training Network 764787 MAESTRO project.
The related research was published in Journal of Energy Chemistry.
Fig. 1. Degradation of the perovskite material with moisture. (Fig by NIU Yunjuan)
Fig. 2. Self-healing Effect (Fig by NIU Yunjuan)
This picture displays what is the novel perovskite solar cell with self-healing effect composed of.(Pic by KONG Fantai)