Abstract: A light-emitting semiconductor device has a semi-insulating semiconductor surface layer overlying a conductive semiconductor layer of a first conductive type. A diffusion region of a second conductive type extends through the semi-insulating semiconductor surface layer and ends in the conductive semiconductor layer. Positive and negative electrode contacts are provided on the upper surface of the device. Nonradiative recombination near the surface of the device is reduced because there is no pn junction in the semi-insulating semiconductor surface layer, and the device structure is suitable for matrix driving.