Patent ID: 7199390

Claim:
A window interface layer of a light-emitting diode, comprising: a) an n-type GaAs substrate having an n-type ohmic electrode at the bottom side thereof; b) an n-type AlGaInP cladding layer formed atop the substrate; c) an undoped AlGaInP active layer formed atop the n-type cladding layer; d) a p-AlGaInP cladding layer formed atop the active layer; e) a p-type window layer made of GaP; f) a p-type ohmic electrode formed atop the p-type window layer; and g) a highly doped p-type interface layer made of Ga x In 1-x P (0.6≦x≦0.9) and interposed between the p-type cladding layer and the p-type window layer wherein the highly doped p-GaInP interface layer possesses a band gap which is higher than that of the active layer and, however, smaller than that of the p-type cladding layer, and wherein its lattice constant lies between GaAs and GaP.