Dr. Niraj Lal, working with the Australian National University, has discovered a technique he thinks could be the beginning of the next-generation of solar cells. The concept is derived from the wings of the blue Morpho Didius butterfly. The surface of the wings is simulated by depositing chemical vapors that self-assemble into telescoped cones with base diameters on the order of half a micrometer. The cones create a refractive index gradient that, like moths’ eyes, reduces reflection. The telescoped edges serve as a diffraction grating, the design of which would control the color, opacity, and finish of a surface. Lal set out to develop a solar cell with a perovskite layer to absorb green visible light and higher wavelengths and a silicon layer to absorb lower wavelengths. The test cell performed with a record, albeit short-lived, 26.4 percent efficiency.