Kodak filed an application US20080315272 on control of 4T pixel floating diffusion capacitance in such a way that it's low for small signals and large for large signals. The pixel schematics is shown below:
Transistor 201 opens only for large signals, increasing floating diffusion capacitance to accomodate the larger charge.
Omnivision's application US20080318358 talks about using indium doping for the photodiode pinning layer. Indium allows for a shallower implant layer with higher concentration than commonly used boron. An indium-boron combination is also applied for the patent.