Investigation of optical properties about Rubrene:MoO3 film

•The absorption spectrum of the Rubrene:MoO3 (in 1:1 wt ratio)mixed film was measured and the results demonstrate that the mixed film shows intensively absorption at the near-infrared region(∼930nm).•To further analysis the affection of MoO3 to Rubrene, the Rubrene:MoO3 films with different proportion of MoO3 were also prepared.•The absorption spectrum of the mixe films demonstrates that the interaction between Rubrene and MoO3 is enhancing with the concentration of MoO3 increasing and the energy is decreasing.•The near-infrared photo-detection device based on Rubrene:MoO3 film was fabricated.•The current-voltage(I–V) characteristic of the device was measured and the infrared detector exhibits an photo dark I / I ratio of ∼8 under a 940nm light illumination with a light intensity of 0.5Wcm-2. Rubrene:MoO3 mixed films(in 1:1 wt ratio) were deposited on quartz substrates using the thermal evaporation technique and the absorption spectrum of the mixed film was measured. The results demonstrate that the mixed film shows intensively absorption at the near-infrared region(∼930 nm) which indicates that the interaction between Rubrene and MoO3 is intensively and induced intermediate level in the band gap of Rubrene and formed charge-transfer complex(CTC). Furthermore, the type of transition is direct allowed transition according to the measurement of optical band gap. To further analysis the affection of MoO3 to Rubrene, the Rubrene:MoO3 films with different proportion of MoO3 were also prepared using the thermal evaporation technique. The absorption spectrum of the mixed films was measured and the results demonstrate that the interaction between Rubrene and MoO3 is enhancing with the concentration of MoO3 increasing and the energy needed by the transition of electrons is decreasing. The near-infrared photo-detection device based on Rubrene:MoO3 film was fabricated. The current-voltage(I–V) characteristic of the device was measured and the results demonstrate that under 5 V bias, the infrared detector exhibits an Iphoto/Idark ratio of ∼8 under a 940 nm light illumination with a light intensity of 0.5 W·cm−2.