TiO2 Nanowires/Poly(Methyl Methacrylate) Based Hybrid Photodetector: Improved Light Detection

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Titanium dioxide (TiO2) nanowires (NWs) are promising for photodetector applications.
• Poly(methyl methacrylate) (PMMA) is a versatile polymer for optoelectronic devices.
• Hybrid structures can enhance photodetector performance.

Purpose of the Study:

• To fabricate and characterize a hybrid photodetector using TiO2 NWs and PMMA.
• To evaluate the UV detection capabilities and performance metrics of the hybrid device.
• To compare the performance of the hybrid device with bare TiO2 NWs.

Main Methods:

• Spin-coating of PMMA polymer onto glancing angle deposited (GLAD) vertically aligned TiO2 NW arrays.
• Fabrication of a hybrid photodetector device.
• Characterization of electrical and photoresponse properties, including external quantum efficiency, photo-responsivity, ideality factor, and transient response.

Main Results:

• The hybrid TiO2 NWs/PMMA photodetector achieved a maximum external quantum efficiency of ~3.08% at 370 nm in the UV region.
• The device exhibited excellent rectification and a constant 1.3 times photo-responsivity under reverse bias (-1 V to -10 V).
• A lower ideality factor (5.1) was observed compared to bare TiO2 NWs (7.1), with sharp turn-on (-0.8 s) and turn-off (-0.9 s) transients.

Conclusions:

• The hybrid TiO2 NWs/PMMA photodetector demonstrates superior performance for UV detection compared to bare TiO2 NWs.
• The integration of PMMA enhances the rectification and photo-responsivity of TiO2 NW-based photodetectors.
• The fast response times indicate potential for high-speed UV sensing applications.