The light-emitting diodes described in this Letter differ from standard type diodes insofar as the amphoteric dopant Si is the dominant impurity on both sides of the junction. The p-n junction is completely solution regrown. The highly compensated p region gives rise to a wide active region up to 50 μ in width. The interesting feature of these diodes is their high external quantum efficiencies at 300°K. Values up to 6% have been measured on diodes, when an antireflecting coat has been applied. © 1966 The American Institute of Physics.