Organic Position-Sensitive Detectors Based on ZnO:Al and CuPc:C60

Area of Science:

• Organic electronics
• Photodetector technology
• Materials science

Background:

• Organic position-sensitive detectors (OPSDs) are crucial for light localization applications.
• Conventional OPSD structures often face limitations in sensitivity and accuracy.
• Bulk heterojunctions offer potential for improved photodetector performance.

Purpose of the Study:

• To fabricate and characterize an inverted structure OPSD using CuPc:C60 bulk heterojunction.
• To investigate the influence of aluminum-doped zinc oxide (ZnO:Al) resistive layer properties on device performance.
• To evaluate the red light sensitivity and position sensing capabilities of the fabricated OPSD.

Main Methods:

• Fabrication of an inverted structure OPSD using copper phthalocyanine (CuPc) and fullerene (C60) bulk heterojunction.
• Preparation of aluminum-doped zinc oxide (ZnO:Al) resistive layer via sol-gel method.
• Characterization of current density-voltage (J-V) properties, resistivity, thickness, and position sensitivity.

Main Results:

• The inverted structure OPSD demonstrated increased sensitivity under red light illumination compared to conventional designs.
• The thickness of the ZnO:Al layer significantly influenced the position characteristics of the OPSD.
• A device with a 620 nm ZnO:Al layer showed accurate position measurements under red laser illumination.
• The OPSD achieved high incident-photon-to-current conversion efficiency (>80% at -3 V) and low linearity error (5.9% at -2 V).

Conclusions:

• The inverted structure CuPc:C60 OPSD offers superior red light sensitivity and accurate position sensing capabilities.
• Optimizing the ZnO:Al resistive layer thickness and resistivity is critical for enhancing OPSD performance.
• The developed OPSD shows promise for applications requiring sensitive and precise light detection.