Since full well capacity depends inversely on diode thickness, the blue and red diodes have ~2-3x higher capacity than the standard green diode. In order to address this difference the green diode can be modified as shown, using the same implants as the stacked diode, resulting in a full well capacity ~2x larger. Additionally, the pinning voltage is smaller, so the output voltage swing is larger. (Lim, et al., 2007 Image Sensor Workshop, 311-314 (2007).

Both the dynamic range (DR) and maximum signal-to-noise ratio (SNR) can be improved by 2PFCTM (~2x) due to large well capacity.