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Updated: Feb 20, 2026
Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
Improved device performances based on Si quantum dot/Si nanowire hetero-structures by inserting an Al2O3 thin layer
Yang Ji1, Yingying Zhai, Huafeng Yang
1National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, and Jiangsu Provincial Key Laboratory of Advance Photonic and Electronic Materials, Nanjing University, Nanjing, 210093, China. junxu@nju.edu.cn.
Adding an aluminum oxide (Al2O3) layer to silicon quantum dot devices on silicon nanowires significantly boosts light emission by over 8-fold. This layer passivates surfaces and confines carriers, enhancing electroluminescence in these optoelectronic devices.
Area of Science:
- Optoelectronics
- Materials Science
- Nanotechnology
Background:
- Silicon quantum dots (Si QDs) are promising for light-emitting devices.
- Si QD devices on Si nanowire arrays aim to improve light extraction.
- Device performance is often limited by surface recombination in Si nanowires.
Purpose of the Study:
- To enhance the electroluminescence of Si QD-based light-emitting devices.
- To investigate the role of an Al2O3 thin layer in improving device performance.
- To understand the mechanisms behind the performance enhancement.
Main Methods:
- Fabrication of Si QD-based light-emitting devices on Si nanowire arrays.
- Introduction of an Al2O3 thin layer between Si QDs and Si nanowires.
- Characterization using electron spin resonance, capacitance-voltage, and conductance-voltage measurements.
Main Results:
- A significant electroluminescence enhancement of approximately 8.5 fold was achieved with the Al2O3 layer.
- The Al2O3 layer provides chemical passivation, reducing surface defect states of Si nanowires.
- The Al2O3 layer acts as a barrier, confining carriers in the Si QD layer via fixed negative charges and a potential barrier.
Conclusions:
- The Al2O3 thin layer effectively improves the performance of Si QD/Si nanowire heterostructures.
- Carrier confinement and surface passivation by Al2O3 promote radiative recombination.
- This approach offers a viable strategy for developing efficient Si-based light-emitting devices.
