Near infrared organic photodetector utilizing a double electron blocking layer

Area of Science:

• Organic electronics
• Photodetector technology
• Materials science

Background:

• Organic photodiodes (OPDs) are crucial for near-infrared (NIR) detection.
• Electron blocking layers (EBLs) are essential for optimizing OPD performance.
• Existing EBL materials like molybdenum (VI) oxide (MoO3) and poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) have limitations.

Purpose of the Study:

• To develop and investigate a novel double electron blocking layer (EBL) for NIR organic photodiodes (OPDs).
• To enhance the on/off current ratio and detectivity of OPDs using a sequential MoO3/PEDOT:PSS double EBL structure.
• To compare the performance of the double EBL with single EBL configurations.

Main Methods:

• Fabrication of OPDs using a sequential deposition of MoO3 and PEDOT:PSS to form a double EBL.
• Characterization of OPD performance, including on/off current ratio and detectivity at NIR wavelengths (800 nm).
• Comparative analysis of device performance with single MoO3 EBL and single PEDOT:PSS EBL devices.

Main Results:

• The double EBL structure achieved an on/off current ratio of 1.36 x 10^4 at -1V, significantly outperforming single EBLs.
• The detectivity at 800 nm reached 4.90 x 10^11 Jones, marking a substantial improvement over single EBL devices.
• The double EBL demonstrated superior performance compared to both MoO3 and PEDOT:PSS single EBLs.

Conclusions:

• Sequential deposition of MoO3 and PEDOT:PSS creates an effective double EBL for NIR organic photodiodes.
• The developed double EBL significantly boosts the on/off current ratio and detectivity of OPDs.
• This approach offers a promising pathway for high-performance NIR photodetector development.