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Published on: January 19, 2018
Single-crystal organic charge-transfer interfaces probed using Schottky-gated heterostructures.
Ignacio Gutiérrez Lezama1, Masaki Nakano, Nikolas A Minder
1DPMC and GAP, University of Geneva, 24 quai Ernest Ansermet, CH1211 Geneva, Switzerland.
Nature Materials
|July 24, 2012
Summary
Investigating organic semiconductor interfaces reveals that electron transport, not just charge transfer, drives conductivity. This study highlights Schottky-gated heterostructures for understanding molecular semiconductor behavior.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Organic Electronics
Background:
- Organic semiconductors are typically insulators when undoped.
- Heterointerfaces between organic semiconductors can exhibit high electrical conductivity.
- The mechanisms and charge carriers responsible for this interfacial conductivity are not fully understood.
Purpose of the Study:
- To investigate the nature of charge carriers and transport mechanisms at organic semiconductor interfaces.
- To explore the potential of Schottky-gated heterostructures for studying interfacial phenomena.
Main Methods:
- Fabrication of Schottky-gated heterostructures using rubrene and PDIF-CN(2) single crystals.
- Measurement of gate-modulated conductivity.
- Analysis of temperature-dependent electron mobility and density.
Main Results:
- Interfacial transport is dominated by electrons.
- Electron mobility exhibits band-like behavior from room temperature down to ~150 K.
- High electron mobility (~1 cm(2) V(-1) s(-1)) was observed at 30 K.
- Electron density shows a linear decrease with temperature, consistent with band diagram predictions.
Conclusions:
- The study elucidates the electronic structure of rubrene/PDIF-CN(2) interfaces.
- Schottky-gated organic heterostructures are effective tools for investigating transport in molecular semiconductors.
- Electron transport, rather than just charge transfer, is key to understanding interfacial conductivity.
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