The near-band emission mechanisms and deep levels of pure green LED has been studied from 77K to room temperature.The samples were fabricated by an overcompensation liquid phase epitaxy method.The peak wavelength of LEDs at 300K was 555nm. Experimental evidences are presented to the emission of dominating centers at 77K

originating from D-A pair transition. When decay time increases

peaks shift apparently toward low energy as a consequence of the distance dependence of the Coulomb interaction. Also

exciton transitions were observed at 77K and the free-exciton recombination did not decay-exponentially. So that it becomes the dominant emission mechanism at room temperature.The near-infrared electroluminescence spectra of N-free GaP LED are complicated. Three overlapping broad emission; bands were observed and decomposed. Their spectra fit Gaussian line shapes and peak energies are 1080nm(1.15eV)

1260nm(0.98eV)and l510nm(0.82eV)

respectively. The 1080nm and 1510nm bands are related to the presence of oxygen and 1260nm band is associated with different recombination processes

involving the PGa antisite defect.