The effect was investigated of growth temperature on the photoluminescence efficiency of MBE-grown n-GaAs/N-AlGaAs single-heterostructure (SH) layers doped with Si. At growth temperatures higher than 700°C, high optical quality Si-doped N-AlxGa1-xAs layers in the range 0≤x<0. 3 were obtained with photoluminescence intensity comparable to that of LPE material. The lateral uniformity of the n-GaAs layer in one of the SH wafers was evaluated by measuring the light output of fabricated Zn-diffused LED's. The variation of light output of the 1039 tested diodes was less than 3.5%, a significantly smaller variation than that obtained from the same geometry LED's made by LPE. These results suggest that MBE is a more promising epitaxial growth technique than conventional techniques for application to integrated optics.