An Electrically Modulated Single-Color/Dual-Color Imaging Photodetector

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Developing advanced photodetectors is crucial for imaging applications.
• Hybrid organic-inorganic materials offer unique optoelectronic properties.

Purpose of the Study:

• To develop an electrically modulated single-/dual-color imaging photodetector.
• To achieve fast response speeds and tunable photodetection capabilities.

Main Methods:

• Fabrication of a hybrid film using a small molecule (COi 8DFIC) and perovskite (CH3NH3PbBr3).
• Characterization of the photodetector's optical and electrical properties.
• Development of a physical model based on band energy theory.

Main Results:

• The photodetector exhibits dual-color detection with cut-off wavelengths at ≈544 nm and ≈920 nm.
• Achieved peak responsivities of 0.16 A W⁻¹ (≈525 nm) and 0.041 A W⁻¹ (≈860 nm) with fast response (≈10² ns).
• Operates in a single-color mode (≈475 nm) under 0.6 V bias with a peak responsivity of 0.09 A W⁻¹ and fast response (≈10² ns).

Conclusions:

• The type-I heterojunction enables facile transformation from dual-color to single-color imaging via bias voltage.
• The developed photodetector demonstrates tunable single-/dual-color photodetection with high performance.
• This work paves the way for solution-processed multifunctional photodetectors in complex imaging scenarios.