Nanoscale color sensors made on semiconducting multi-wall carbon nanotubes

Sub-micron color sensors are developed, using carbon nanotubes (CNTs). The color sensor consists of an array of two photodiodes with different spectral responses, fabricated using controlled electric peeling-off and doping-free techniques on a single semiconducting double-wall CNT. The CNT photodiodes exhibit intrinsic broad spectral responses from 640 to 2,100 nm, large linear dynamic ranges of over 60 dB, and sub-micron pixel size. This method explores the unique properties of multi-wall CNTs, and may be readily used for large-scale fabrication of high performance color sensor arrays, when arrays of parallel multi-wall CNTs become available.