Color pixels made of nanowires offer new paradigm for digital cameras

Most of today's digital cameras achieve color by using red, green, and blue Bayer color filters through which light passes on its way to the camera's image sensors, which then convert the light into electrical signals. Although this color filter technology is very widespread, it has some disadvantages related to durability, low absorption coefficient, and fabrication complexity. In addition, the absorbed light in the color filter cannot be converted into photocurrent. To maximize the efficiency in the trends of higher pixel density, this light needs to be converted to photocurrent.

n the past few years, researchers have been investigating new ways to achieve color in digital cameras that don't rely on conventional organic dye filters. In a new paper published in Nano Letters, a team of researchers from Harvard University in Cambridge, Massachusetts, and Zena Technologies Inc., in Topsfield, Massachusetts, have presented a new filter-free approach to color imaging. The technique uses silicon nanowires with different radii to absorb specific wavelengths, and thus colors, of light and convert the light into photocurrent.