Quantum　dots　(QDs)　have　showed　great　potential　for　next-generation　lighting　and　display　technologies.　However,　its　stability　is　still　one　of　the　key　problems　that　limit　its　practical　application.　In　this　paper,　by　comparing　the　specific　surface　area　(SSA)　and　pore　width　of　aluminum　oxide　(AlOx)　and　silicon　oxide　(SiO2)　barrier　layers,　the　relationship　between　the　porosity　of　barrier　layers　and　the　stability　of　QDs　was　studied.　The　results　showed　that　the　synthesized　SiO2-QD-AlOx,　which　has　the　smallest　SSA　in　the　synthesized　QD　composites,　exhibited　the　best　stability　on　the　quantum　dot　diffuser　plate　(QD-DP).　Moreover,　the　operational　lifetime　(T80)　at　450　nm　blue　light　excitation　was　increased　by　a　factor　of　3.41　compared　to　that　of　bare　QDs.　Meanwhile,　the　prepared　QD-DP　containing　dense　SiO2-QD-AlOx　composites　significantly　improved　the　resistance　to　light,　heat,　moisture　and　oxygen.　Finally,　the　prepared　QD-DP　was　assembled　into　a　Mini-LED　TV　with　a　wide　color　gamut　and　excellent　display　performance　(a　color　gamut　of　157.4　%　for　commercial　normal　TV,　and　107.19　%　for　the　National　Television　System　Committee　(NTSC　1931)).　This　technique　provides　favorable　guide　for　effectively　enhancing　the　stability　of　QDs　in　lighting　and　display　technologies.