If you have ever raised chickens from chicks you have probably discovered that juvies (like all teenagers) don't like going to bed.
Here's a trick: When it is time to move the chicks from the brooder to the coop, turn a light on in the coop just before dusk (battery op. lights with timer work great) and the chicks will jump right in as soon as it starts getting dark. Do this for a couple of weeks and you're golden. Be sure to turn off lights when you close the door.