We need the following components:
one LTR-4206E phototransistor one lithium CR2032 battery (3 V) 2N3904 transistor 1 K resistor
Photos of these components:


Progress: First, take the Transistor and resistor and solder them as shown in the figure:


Next, solder a phototransistor to this design:


Next, we attach the LED:

And then the power source:


And now we look at what we got:


This light will turn on when it gets dark
