facebook icon in widget

I am trying to add a facebook link/icon to a widget with this code:

but the ue800 icon is defaulting to a non-boxed facebook icon. Is there a different way to do this? I tried also using the title=icon-facebook-square which also did not seem to work. I had trouble with fontello – if I choose icons to download they are not in .zip format so I wasn’t sure how to upload it or install a different font. I am ok with using entypo.

thanks