Application of the DPC method to Schottky-barrier photodiode with interfacial layer

The differential photocurrent (DPC) method has been extended for the Schottky-barrier photodiode with the interfacial layer by taking the effect of the interfacial layer into account. The hole diffusion length L
p
in n-type GaAs
0.62
P
0.38
layer was obtained to be 1.9 µm within the accuracy of 7 percent from the relation between the absorption coefficient α and the DPC-to-photocurrent ratio (
\Delta I_{p}/ \DeltaW)_{W=0}/(I_{p})_{W=0}
.