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CsPbBr3 Quantum Dot Sensitization Enabled Type-III SnSe2/MoTe2 Heterojunction for Fast and Self-Powered Visible
Dongxue Wang1, Zhaoli Chen1, Jiabin Li1
1Guangdong Provincial Key Laboratory of Chip and Integration Technology, School of Electronic Science and Engineering (School of Microelectronics), Faculty of Engineering, South China Normal University, Foshan, People's Republic of China.
This study introduces a novel self-powered visible photodetector using CsPbBr3 quantum dots and a type-III SnSe2/MoTe2 heterojunction. The device achieves high responsivity and fast response times for advanced optical applications.
Area of Science:
- Materials Science
- Nanotechnology
- Optoelectronics
Background:
- Self-powered photodetectors are crucial for low-power electronic devices.
- Type-III 2D heterojunctions offer zero-bias operation but face challenges in visible light responsivity due to limited photocarrier generation.
- Atomically thin absorbers in photodetectors often struggle with efficient light absorption and carrier separation.
Purpose of the Study:
- To develop a sensitized self-powered visible photodetector with enhanced responsivity.
- To investigate the integration of CsPbBr3 quantum dots (QDs) with a type-III SnSe2/MoTe2 heterojunction.
- To leverage the built-in electric field at the heterojunction interface for improved photocarrier generation and reduced recombination.
Main Methods:
- Fabrication of a heterojunction device using SnSe2 and MoTe2.
- Integration of CsPbBr3 quantum dots as a sensitizer onto the heterojunction.
- Characterization of the photodetector's performance under visible light illumination at zero bias.
- Analysis of the built-in potential difference and its effect on carrier dynamics.
Main Results:
- The sensitized photodetector achieved a responsivity (R) of 764.4 mA W⁻¹ and an external quantum efficiency (EQE) of 245.2% under 405 nm illumination.
- A high specific detectivity (D*) of 2 × 10¹² Jones and a microsecond-scale response time (740/960 µs) were recorded.
- The built-in potential difference between CsPbBr3 QDs and SnSe2 facilitated directional hole injection, enhancing carrier collection and suppressing recombination.
- The device demonstrated stable cycling behavior and potential for imaging and optical logic applications.
Conclusions:
- Coupling a QD sensitizer with a type-III 2D heterojunction is a viable strategy for significantly enhancing self-powered visible photodetection.
- The developed photodetector exhibits excellent performance metrics, including high responsivity, detectivity, and fast response time.
- This approach offers a promising pathway for next-generation optoelectronic devices operating at zero bias.
