A 60-year puzzle in organic solar cracks: rigid molecules slash the energy lost turning light into power

Organic solar cells — the kind that could be printed onto windows, curtains and clothing — have been held back for six decades by a stubborn leak: too much of the sunlight's energy is lost in the instant light becomes electricity. A team at Chiba University led by Professor Hirohiko Fukagawa has now found where the leak's boundary lies. Testing five light-absorbing 'donor' materials against 15 partners, and measuring with two specialised spectroscopies, they showed that stiff, rigid donor molecules can shrink a key energy penalty — the binding energy that traps charges before they can flow — to a tenth of an electron-volt or less. The work, published in the peer-reviewed journal Advanced Materials, gives designers a map: keep this number under that line, and flexible solar gets dramatically more efficient.

SDG 9 · Industry, innovation and infrastructure — Mechanism: tech innovation