A fundamental study to address the feasibility of rare earth doping of semiconductors(III-V, Silicon, and SiGe) for light emitting devices will be conducted. The approach is to introduce erbium in the form of moleclules of erbium and another impurtiy(oxygen or nitrogen). This will be achieved by control of growth chemistry and use of novel precursors, which are designed to decompose in sucha a way as to form Er-O and Er-N radicals on the growth surface and be incorporated in this form into the layer. Capture of carriers by the impurity part of a dopant molecule followed by energy transfer to erbium is expected to provide an efficent excitation route of intra-4f shell luminescence. %%% This research will investigate a new method for obtaining light emission from semiconductors. Potential benefits include the ability to provide novel devices and optical interconnects in high performance electronic and photonic devices and integrated circuits used in computing, information processing, and telecommunications.