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Updated: Feb 11, 2026
08:12
Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
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Strain-engineered inverse charge-funnelling in layered semiconductors.
Adolfo De Sanctis1, Iddo Amit2, Steven P Hepplestone2
1Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF, UK. a.de-sanctis@exeter.ac.uk.
Nature Communications
|April 27, 2018
Summary
Researchers observed the inverse charge-funnel effect in HfS2 using strain-induced electric fields. This led to a significant enhancement in phototransistor responsivity, paving the way for efficient solar cells.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Electrical Engineering
Background:
- External electric fields control charge dynamics crucial for information processing.
- Engineered built-in electric fields at material interfaces are vital for photovoltaics and opto-electronics.
- Atomically thin semiconductors offer novel pathways for electric field generation and charge transport.
Purpose of the Study:
- To directly observe the inverse charge-funnel effect electrically.
- To investigate the role of spatially resolved strain-induced electric fields in HfS2.
- To enhance phototransistor performance using engineered electric fields.
Main Methods:
- Fabrication of a thin sheet of Hafnium disulfide (HfS2).
- Generation of deterministic and spatially resolved strain-induced electric fields.
- Electrical characterization of a phototransistor incorporating the HfS2 channel.
Main Results:
- First direct electrical observation of the inverse charge-funnel effect in HfS2.
- Demonstration of charges being driven by spatially varying electric fields.
- A 350% enhancement in phototransistor responsivity was achieved.
Conclusions:
- Strain-induced electric fields in HfS2 enable novel charge transport mechanisms.
- The inverse charge-funnel effect can significantly boost phototransistor performance.
- Findings suggest potential for designing highly efficient photovoltaic devices.
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