The best replacement for photocell is photoresistor.

The best alternatives to photocell are rated as following:
★★★★★  photoresistor
★★★★★  photodiode
★★★  phototransistor
★★★  pir

Your alternative for photocell is not listed? Suggest!
Speaking about photocell, one probably shouldn't forget about timer.

Other search terms related to photocell and their ratings are:
★★★★★ timer
★★ timer switch
★★ motion sensor
★ contactor
★ pir
★ lighting contactor
transformer
compact fluorescent
You have in mind a companion for photocell and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of photocell in all years. Click on graph for more.
photocell
photoresistor
photodiode