i need something that can detect light and do it quickly
all i really found was this
or would this work?
Depends on how much light, what kind of light, and the definition of "quickly".
light from an led, and quickly like a seconds or even faster
"Seconds" in electronics is generally considered slow. The photocell should work fine.
You choice is between an LDR (light-dependent resistor) and a phototransistor. LDRs take a few seconds to react to changes from bright light to dark, otherwise they are fast enough for your application. Phototransistors are very fast, their response time is sub-millisecond.
Okay thanks guys