Erbium doped GaAs was grown by metal‐organic chemical vapor deposition using a novel liquid precursor: tris(n‐butylcyclopentadienyl)erbium [Er(C4H9C5H4)3]. The morphology was excellent at growth temperatures near 620 °C. Based on a simple model for the excitation dependence of the emission, the nonradiative Auger‐type process was estimated to be nearly five times that of the energy transfer process from bound excitons to the Er3+ions that subsequently resulted in the Er‐related light emission. Temperature induced quenching of the emission was found to be dominated by transitions with an activation energy of 74 meV.