摘要 |
A semiconductor color sensor implemented without the use of color filters. Fabricating photodiodes using different semiconductor materials provide photodiodes with different sensitivities vs. wavelengths. A first embodiment uses photodiodes with different junction depths. A shallow junction depth produces a photodiode with its sensitivity peak in shorter wavelengths, while a deeper junction depth produces a photodiode with its sensitivity peak in longer wavelengths. Amorphous as well as crystalline structures may be used. A second embodiment uses photodiodes with different materials, such as Silicon-Germanium (SiGe) which has a longer wavelength peak sensitivity, and Silicon (Si) which has a shorter wavelength peak sensitivity in comparison. More than two photodiodes having different wavelength sensitivities may be used. Sensing current ratios between pairs of diodes allows color balance to be maintained.
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