Patent ID: 7768048

Claim:
An infrared sensor comprising: a substrate; and a compound semiconductor stacked layers formed on said substrate by stacking a plurality of compound semiconductor layers, said compound semiconductor stacked layers comprising: an n-type doped compound semiconductor layer formed on said substrate, said n-type doped compound semiconductor layer composed of an n-type doped material and including indium and antimony; a compound semiconductor light absorption layer formed on said n-type doped compound semiconductor layer, said compound semiconductor light absorption layer composed of a non-doped or p-type doped material including indium and antimony; and a p-type doped compound semiconductor layer formed on said compound semiconductor light absorption layer, said p-type doped compound semiconductor layer composed of a material that is p-type doped at a higher carrier density than said compound semiconductor light absorption layer and has a larger band gap than said n-type doped compound semiconductor layer and said compound semiconductor light absorption layer, wherein said p-type doped compound semiconductor layer functions as a barrier layer.