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Updated: Jun 4, 2026
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All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
D- shallow donor near a semiconductor-metal and a semiconductor-dielectric interface
Y L Hao1, A P Djotyan, A A Avetisyan
1Department of Physics, University of Antwerpen, Antwerpen, Belgium.
Summary
The binding energy of negatively charged donors (D(-)) near semiconductor interfaces depends on interface type and donor position. Semiconductor-metal interfaces can enhance D(-) binding, while semiconductor-dielectric interfaces reduce it, leading to instability.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Chemistry
Background:
- Understanding donor impurities in semiconductors is crucial for electronic devices.
- The behavior of charged donors (D(-)) near interfaces is complex due to image charge effects and electron correlation.
- Previous studies often simplified interface interactions or neglected electron correlation in D(-) systems.
Purpose of the Study:
- To calculate the ground state energy and wavefunction extent for D(-) near semiconductor interfaces.
- To investigate the influence of interface type (semiconductor-metal vs. semiconductor-dielectric) on D(-) binding energy.
- To analyze the role of image charges and electron correlation in D(-) stability near interfaces.
Main Methods:
- Application of the effective mass approximation.
- Utilizing a variational two-electron wavefunction.
- Inclusion of image charges from the interface and electron-electron correlation effects.
Main Results:
- For semiconductor-metal interfaces, D(-) binding energy increases for donor positions d > 1.5a(B) due to image charge attraction.
- Near semiconductor-metal interfaces (d < 1.5a(B)), D(-) binding energy decreases, leading to unbound states.
- For semiconductor-dielectric interfaces, D(-) binding energy is reduced compared to bulk, with rapid unbound states as the donor approaches the interface.
Conclusions:
- Interface type critically determines D(-) stability and binding energy.
- Semiconductor-metal interfaces can stabilize D(-) at larger distances but destabilize it closer to the interface.
- Semiconductor-dielectric interfaces generally destabilize D(-), making it more prone to dissociation.
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