This　paper　reports　the　effect　of　Cu2O　nanoparticles　on　the　temperature　sensing　properties　and　optical　switching　of　Poly-(Dioctylfluorene).　A　surface　type　capacitive　temperature　sensor　and　optical　switch　has　been　fabricated　by　depositing　720　nm　thin　layer　of　F8:Cu2O　on　pre-patterned　silver　(Ag)　electrodes,　using　optical　lithography　and　shadow　masking　followed　by　vacuum　thermal　deposition.　The　effect　of　temperature　on　the　electrical　resistance　for　sensor　and　as　optical　switch　by　exposing　light　has　been　investigated.　The　sensor　responded　exponentially　with　increasing　temperature,　also　exposing　to　light　it　work　as　an　optical　switch.　The　on　off　of　this　optical　switch　is　will　explained　by　graph.　Scanning　Electron　Microscopy　has　been　employed　to　study　the　morphology　of　F8:Cu2O　thin　film.　These　results　demonstrated　that　the　temperature　sensor　and　optical　switch　made　of　F8:Cu2O　have　excellent　accuracy　and　performance.