Researchers in Australia have resolved a fundamental challenge preventing the wide uptake of next-generation perovskite solar cells. Their work helps the cells cope with exposure to light.
Metal-halide perovskites, a class of hybrid organic-inorganic materials, provide a cheap, flexible and highly promising pathway for efficient solar photovoltaics, as well as light emissive devices and fast x-ray detectors.
However, since gaining prominence over the last decade, perovskite materials have presented scientists and engineers with several problems precluding their widespread use in commercial applications.
Among these is light-induced phase segregation, in which illumination, such as sunlight, disrupts the carefully arranged composition of elements within mixed-halide perovskites.
This in turn leads to instability in the material’s bandgap, interfering with the wavelengths of light absorbed, while reducing charge-carrier conduction and the efficiency of devices, explains a statement.
Members of the ARC Centre of Excellence in Exciton Science have now shown that high-intensity light will undo the disruption caused by light at lower intensities, and that this approach can be used to actively control the material’s bandgap.
The implications of the findings are significant, with researchers now able to retain the optimal composition of elements within mixed-halide perovskites when they are exposed to light, necessary for its use in solar cells.
Scientist Dr Chris Hall said: “A lot of people have approached this problem by investigating ways of suppressing light-induced disorder, such as looking at different compositions of the material or changing the dimensions of the material.
“What we’ve shown is that you can actually use the material in the state that you want to use it, for a solar cell – all you need to do is focus more light onto it. We’ve done the fundamental work and the next step is to put it into a device.”
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