On/Off with IR Reciever
If all you need to do is turn the power on (and have it stay on), then here is one way:



The output of the IR Receiver is used to apply a positive pulse of current to the base of Q2, which grounds the gate of M1, turning it on. This puts 9V on the top pf R4 so Q2s base is supplied with current to keep it on after the IR receiver pulse has stopped.

If you did want to turn it off, you need to either switch the 9V source off, or ground Q2s base temporarily (e.g. a switch to ground)