I've made a device that lights an LED at a very low current (<10 microamps) as a very dim indicator for use in the dark.
At its simplest, the circuit is a 3V coin battery + resistor (300K-1M ohms) + LED.
I'd like it to turn off when there's ambient light in the room and, ideally, draw no power whatsoever to save the small battery it runs on.
The darkness detectors I'm aware of, however, use a transistor and photo detector to accomplish this (see https://www.buildcircuit.com/darklight-sensor-using-transistor/), and typically draw power in ambient light when the LED is turned off. These work at when running the LED at ~10-20mA, but just tinkering, I haven't been able to make these function at the low <10uA currents I'm trying to work with.
Any ideas on a better way to switch off a low current LED circuit entirely when light is detected?