Here　we　report　strong　enhancement　in　ultraviolet-photoluminescence　(UV-PL)　of　ZnO　thin　films　(grown　on　a　SiC　substrate)　covered　by　monolayer　dielectric　fused　silica　or　polystyrene　microspheres　with　diameters　ranging　from　0.5　to　7.5　mu　m.　The　excited　light　scatted　in　the　film　is　collected　by　the　microspheres　to　stimulate　whispering　gallery　modes,　by　which　the　internal　quantum　efficiency　of　spontaneous　emission　is　enhanced.　Meanwhile,　the　microsphere　monolayer　efficiently　couples　emitted　light　energy　from　the　luminescent　film　to　the　far-field　for　PL　detection.　A　UV-PL　enhancement　up　to　10-fold　via　a　5-mu　m-diameter　microsphere　monolayer　is　experimentally　demonstrated　in　this　work.　The　unique　optical　property　of　microsphere　in　photoluminescence　(PL)　enhancement　makes　them　promising　for　high-sensitivity　PL　measurements　as　well　as　design　of　photoelectric　devices　with　low　loss　and　high　efficiency.　(C)　2014　Optical　Society　of　America