Are There Fast-Responding Photoresistors for Light Sensing?

[planety_vuki]

Are there any easy to obtain and fast responding photoresistors out there ? The resistance of material must decrease when light in shining on it, and the response must be fast.

Note: I know that photodiodes respond extremely fast but they must be used coupled with a transistor to amplify the detection. Also photodiodes response is not decrease in resistance but generation of voltage.

I use a cheap CdS photoresistors but they are too slow, especially when going from light to dark.

 

[planety_vuki]

Oh and response must be huge. CdS photoresistors, although slow responding, change their resistance from almost infinity to almost zero. I mean what's the mean if material changes resistance from say 1000 ohm to 800 ohm or something like that.

 

[planety_vuki]

does anybody have experience with POLYVINYLCARBAZOLE ?