Photovoltaics with piezoelectric core-shell nanowires
Fredrik Boxberg1, Niels Søndergaard, H Q Xu
1Division of Solid State Physics, Lund University, Lund, Sweden.
Nano Letters
|March 3, 2010
Summary
A new piezoelectric field in strained semiconductor nanowires was theoretically discovered. This finding offers novel device concepts for efficient solar energy conversion by separating electron-hole pairs.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Semiconductor nanowires are crucial for advanced electronic and optoelectronic devices.
- Strain engineering in core-shell nanowires can modify their electronic properties.
- Understanding internal electric fields is key to optimizing device performance.
Purpose of the Study:
- To theoretically discover and characterize a generic piezoelectric field in strained core-shell compound semiconductor nanowires.
- To investigate the origin and behavior of this internal electric field.
- To explore the potential applications of this phenomenon in solar energy conversion.
Main Methods:
- Development of an analytical model.
- Numerical simulations based on electroelastically coupled continuum elasticity theory.
- Analysis of lattice-mismatch-induced strain in epitaxial core-shell nanowires.
Main Results:
- A generic piezoelectric field is theoretically discovered along the nanowire axis in strained core-shell nanowires.
- This field arises from atomic layer displacements due to lattice mismatch.
- The piezoelectric field is present in both zinc blende and wurtzite crystalline structures.
Conclusions:
- The discovered piezoelectric field can effectively separate photon-generated electron-hole pairs.
- This presents a novel device concept for enhanced solar energy conversion.
- The findings open new avenues for designing efficient semiconductor nanodevices.
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