|Patent Cooperation Treaty||Reference for National Filings||WO2017132283||08/03/2017||2016-085|
Conventional cameras achieve color imaging by patterning organic dye color filters on top of photo detectors. However, due to the low absorption coefficients, organic dye filters cannot be made thinner than a few hundred nanometers, forbidding the realization of very small pixels. In addition, they are not durable under ultraviolet illumination or high temperature. Alternatively, optically thick plasmonic color filters have been realized, which can achieve pixel size down to a few microns. They are also superior to organic dyes regarding stability and design flexibility. However, the plasmonics color filters are still based on the conventional filtering scheme, which is intrinsically ineffective.
Researchers at the University of California, Berkeley have developed a mechanism to achieve sub-micron pixel detection with very high photon efficiency. This novel mechanism is based on 3D semiconductor particles, which are more sturdy and easier to fabricate comparing to aforementioned techniques. At sub-micron pixel size, these resonant nano-structures outperform conventional color filters, which are limited by detrimental crosstalk between neighboring pixels.
High photon efficiency
Less crosstalk between neighboring pixels