Problem:

The charge transport layer, playing a critical role in high-performance perovskite solar cells (PSCs), suffers from significant non-radiative recombination, limiting their power conversion efficiencies.

Solution:

Capsaicin (C₁₈H₂₇NO₃)

Qin-ye Bao, a professor in the School of Physics and Electronic Science at East China Normal University in Shanghai and his colleagues have found a secret ingredient for making solar panels that absorb the sun’s energy more efficiently. Capsaicin,

C₁₈H₂₇NO₃ is the organic chemical that gives chili peppers (from the genus Capsicum) their spicy sting, also improves perovskite solar cell efficiency.

Bao and his team suspected that capsaicin might have an energy-boosting effect because it can free up electrons that can go on to carry charge. They tested the capsaicin-treated solar cells in the laboratory by exposing them to artificial light to simulate sunlight and measuring the electrical current running through them.

Capsaicin made the solar cells more efficient, yielding a power conversion of 21.88 per cent, versus 19.1 per cent without capsaicin. The team then analysed the solar cells with spectroscopy while conducting energy and found that the addition of capsaicin did indeed lead to a greater number of free electrons available to conduct current at the solar cells’ surface. This reduced energy leakage via heat.

Conflicts between farmers and elephants have long been widespread in African and Asian countries, where elephants nightly destroy crops, raid grain houses, and sometimes kill people. Farmers have found the use of chilies effective in crop defense against elephants.

Elephants do not like capsaicin, the chemical in capsicum chilies that makes them hot. Because the elephants have a large and sensitive olfactory and nasal system, the smell of the chili causes them discomfort and deters them from feeding on the crops. By planting a few rows of the pungent fruit around valuable crops, farmers create a buffer zone through which the elephants are reluctant to pass.

Discover Solution 349: Photovoltaic road surfacing

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