The behaviour of bismuth in GaP is interesting not only because of the possibility of highly efficient radiative recombination at low temperature

but also the "rich" fine structure of the luminescence spectrum

which has not yet been finally identified.An investigation on the luminescence spectra of GaP grown by epitaxy from Ga-Bi melts containing 10at% Bi has been made.Photoluminescence measurements were performed at temperatures between 4.2K-110K.The samples were excited by the 4880Åline from an argon-ion laser.The excitation power was 140mW.The spectra were taken by using an ASI-50D double grating monochromator with a R106 photo-multiplier.The output signal of the photomultiplier was amplified by a lock-in amplifier and recorded by X-Y recorder.