In　this　paper,　the　mixed　films　with　different　rubrene-to-MoO3　ratios　are　deposited　on　the　substrates　of　Si,　indium　tin　oxide　and　quartz　glass　by　using　the　thermal　evaporation　technique.　First,　these　films　are　characterized　by　atomic　force　microscopy　and　X-ray　diffraction　in　order　to　identify　their　surface　morphology　and　their　structure　properties.　The　results　show　that　all　the　films　are　amorphous　and　the　film　has　the　best　flatness　when　the　rubrene-to-MoO3　ratio　is　2:1.　Second,　the　optical　properties　of　the　mixed　films　are　investigated　by　both　photoluminescence　(PL)　spectra　and　absorption　spectra.　The　optical　band　gap　of　rubrene　and　MoO3　are　2.2　eV　and　3.49　eV　respectively　and　there　is　almost　no　absorption　about　rubrene　and　MoO3　in　the　near-infrared　(NIR)　region.　However　the　PL　spectrum　shows　a　peak　in　NIR　region　and　it　indicates　that　the　interface　between　rubrene　and　MoO3　possesses　an　abrupt　discontinuity　at　the　vacuum　level,　resulting　in　electron　wave　functions　overlapping　and　charge-transfer　complex　(CTC)　forming.　The　intermediate　state　within　the　original　band　gap　of　rubrene　with　energy　of　1.25　eV　is　induced　by　the　CTC,　which　suggests　the　possibility　of　charge　transfer　exciton　generated　upon　NIR　excitation.　The　absorption　spectra　of　the　mixed　films　show　that　there　is　an　obvious　absorption.　All　the　films　have　the　same　absorption　peak　except　the　film　with　a　rubrene-to-MoO3　ratio　of　4:1　and　it　indicates　that　the　concentration　of　MoO3　has　almost　no　influence　on　the　absorption　of　the　mixed　films.　The　optical　band　gaps　of　the　mixed　thin　films　are　calculated　in　a　spectral　range　of　345-1035　nm　according　to　the　Tauc　equation,　and　the　results　show　that　the　optical　band　gap　of　the　film　with　a　rubrene-to-MoO3　ratio　of　2:1　is　narrowest　(similar　to　2.23　eV).　In　order　to　study　the　electrical　characteristics　of　the　mixed　films,　an　Al/rubrene:　MoO3/ITO　device　is　fabricated.　The　current　density-voltage　(J-V)　characteristic　is　also　investigated.　The　analysis　of　the　J-V　measurement　for　the　device　indicates　that　the　current　conduction　in　the　Al/rubrene:　MoO3/ITO　device　is　Ohmic　type　when　the　rubrene-to-MoO3　ratios　are　4:1　and　2:1,　and　it　is　Schottky　type　when　the　ratio　is　other　value.　The　current　for　rubrene-to-MoO3　ratio　of　1:1　is　larger　than　that　for　1:2,　which　indicates　that　the　contact　is　better　when　the　surface　is　more　smooth.　These　properties　of　the　mixed　films　can　result　in　the　applications　in　the　near-infrared　region.