An LPE growth method is described for the growth of InGaAsP on (1, 0, 0) GaAs over a wide range of band-gap energy. Melt compositions and distribution coefficients of elements for lattice-matched growth of various layers are given. Observed band-gap energies and lattice constants of the layers are compared with formerly reported calculations. Photoluminescence spectral shape and spectral-peak energies are discussed in comparison with InGaAsP grown on InP. Doping of Zn and Te for p-type and n-type InGaAsP is also reported.