Efficient visible light emitting diodes have been fabricated from Ga 1-xAlxAs. Epitaxial layers were obtained by a modified solution growth technique. External quantum efficiencies of up to 3.3 have been measured at room temperature on diodes, which had their emission at 1.70 eV. The switching time for the light emission at 300°K was measured to be 60 nsec. © 1967 The American Institute of Physics.