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Pyroelectric-Enhanced Position Sensing and Its Multifunctional Imaging in a Si Nanowire/CdS Core-Shell Heterojunction
Meilin Nie1, Heqing Wen1, Haiyang Jiang1
1Hebei Key Laboratory of Optic-Electronic Information and Materials, College of Physics Science and Technology, Hebei University, Baoding 071002, P. R. China.
Nano Letters
|March 6, 2025
Summary
This study presents novel silicon/cadmium sulfide (Si/CdS) nanowire detectors that exhibit enhanced self-powered position sensing. The pyroelectric effect significantly boosts sensitivity for advanced imaging applications.
Area of Science:
- Materials Science
- Optoelectronics
- Semiconductor Devices
Background:
- Position-sensitive detectors (PSDs) are crucial for optical sensing.
- Silicon/cadmium sulfide (Si/CdS) heterojunctions offer promising optoelectronic properties.
- Improving self-powered operation and sensitivity in PSDs remains a key challenge.
Purpose of the Study:
- To investigate and compare the performance of Si/CdS heterojunction PSDs with planar, pyramid, and nanowire structures.
- To explore the potential of pyroelectric effect enhancement for lateral photovoltaic effect (LPE) based sensing.
- To develop a wavelength-discriminating imaging system utilizing LPE properties.
Main Methods:
- Fabrication of three distinct Si/CdS heterojunction structures: planar, pyramid, and nanowire.
- Systematic characterization of their self-powered capability and lateral photovoltaic effect (LPE) performance.
- Integration of pyroelectric effect to enhance LPE sensitivity and development of a PE-enhanced imaging system.
Main Results:
- The nanowire core-shell structure exhibited superior self-powered capability and LPE performance.
- A broad optical response (405-1064 nm), peak sensitivity of 779.1 mV/mm, and low nonlinearity (6.3%) were achieved.
- Pyroelectric enhancement resulted in a record sensitivity of 11,646.7 mV/mm with ultrafast response times (92-103 μs).
- A PE-enhanced imaging system successfully discerned different laser wavelengths.
- High sensitivity (1177.6 mV/mm) was maintained at a 6 mm working distance, enabling modulation of imaging resolution.
Conclusions:
- Si/CdS nanowire core-shell heterojunctions are highly effective for self-powered position sensing.
- The pyroelectric effect offers a significant pathway to dramatically enhance LPE sensitivity and enable advanced imaging.
- The developed system demonstrates potential for wavelength-selective imaging and resolution control.
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