We report on the photolysis of triethylarsenic, monoethylamine, and monoethylarsine with respect to H-atom formation. For all three molecules, 193-nm excitation followed by a 248-nm laser pulse produces an H-atom signal that is enhanced relative to the signal derived from the sum of the two lasers operating alone. The use of the selectively-deuterated compounds C2D5NH2 and C2H5ND2 clearly demonstrates that significant H-atom enhancement occurs via the ethyl group, at least in the case of monoethylamine. The importance of such photolysis reactions is discussed in terms of the laser-enhanced growth of III-V semiconductor materials.