Upon exposure to several group III trialkyls : trimethylaluminum, trimethylgallium, triethylgallium, and trimethylindium, the bandedge photoluminescence intensity of etched single-crystal n-CdSe samples exhibits a large and irreversible enhancement relative to a vacuum reference ambient. From X-ray photoelectron spectroscopy, this photoluminescence enhancement, which ranges from factors of similar to 3 to 100, appears to correspond to irreversible binding of a group III metal-bearing species to the surface. Subsequent exposure of the sample to butylamine, C4H11N, isomers can partially reverse this enhancement by similar to 10 to 80%, depending upon the amine and group III trialkyl precursor combination, presumably through adduct formation with a group III atom-derived, surface-confined species. The magnitude of the amine interaction appears to be the greatest for combinations of less bulky amines with trimethylaluminum- and trimethylgallium-derived species. Reversible photoluminescence enhancements could be obtained through use of volatile discrete 1:1 trimethylamine adducts of trimethylaluminum and trimethylgallium. These adducts bind to the CdSe surface with an equilibrium constant of similar to 10(4) atm(-1), based on the Langmuir adsorption isotherm model. Implications for the use of these effects in sensing chemical vapor deposition precursor molecules are discussed.