Conduction Band Minima ofGa(As1−xPx)

Photoresponse of surface barriers on samples of $\mathrm{Ga}\left({\mathrm{As}}_{1-x}{\mathrm{P}}_x\right)$ covering the range $0\le x\le \mathrm{I}$ has been measured. Thresholds corresponding to both direct and indirect band-to-band excitations within the semiconductor and also photoinjection from the metal have been identified. The threshold of the direct transition varies with composition from 1.37 eV in GaAs to 2.65 eV in GaP. The indirect transition was followed for $x\gtrsim 0.38$ and again varied linearly from 2.2 eV in GaP to an extrapolated value in 1.62 eV in GaAs. The energy separation of the two conduction band minima in GaAs is in disagreement with previously reported values.