These cheap solar cells work better because they’re flawed

Lead-halide perovskites, cheap solar cell materials packed with structural flaws, achieve efficiency levels approaching silicon cells through an unexpected mechanism that researchers at Austria's ISTA have finally explained. Unlike silicon which requires ultra-pure materials, perovskites benefit from their imperfections—networks of structural defects called "domain walls" that act as highways for electrical charges, allowing them to travel long distances without recombining. This discovery resolves a decade-long scientific mystery and could enable engineering improvements that make these low-cost solar cells commercially viable.