I think this has some potential as a silhouette, but the attempt at masking is too obvious. Given that there is very little detail to bring out in the barn and the tree limbs anyway, I would suggest not bothering to mask them, and just let then stay completely dark. In order to make that complete, I might even be tempted to remove the plants in the foreground that are somewhat illuminated. They don't really provide meaningful content, and would tend to detract from a full silhouette. I'd give that a try, anyway.
I agree with Dave. Simply use a filter or creative white balance to get the sky to sing. Then adjust channel saturation if you want to emphasize a tone.
