The circuit as drawn will not work.
You will need about 2.8 to 3 volts at the base of the transistor before it conducts, and when it does the transistoe and LED will be destroyed as there is no current limiting resistor.
The 1N4001 will clamp the base voltage at 0.6 - 0.7 volts, this will stop this circuit from doing anything at all.
Move the LED to the collector of the transistor, and add a 1K resistor in series with the LED.
Remove the 1N4001, it is not necessary.
JimB