Nope it has to be decorative. ....... Higher management's orders [emoji1]Are you actually looking for a lantern (i.e. something pretty) or just a PIR light?
If a flood would do then these take some beating
http://www.screwfix.com/p/lap-slimline-led-pir-floodlight-black-10w/8300v
More powerful ones higher up the range cost more but the 10W is pretty bright.