1. Fast and efficient photodetection in nanoscale quantum-dot junctions
- Author
-
Arjan J. Houtepen, Michele Buscema, Johannes S. Seldenthuis, Val Zwiller, Maria Barkelid, Yunan Gao, Laurens D. A. Siebbeles, Gilles Buchs, S. Etaki, Ferry Prins, and Herre S. J. van der Zant
- Subjects
Optics and Photonics ,Materials science ,Time Factors ,Light ,Photochemistry ,Photodetector ,FOS: Physical sciences ,Bioengineering ,Electrons ,Photodetection ,Quantum Dots ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Nanotechnology ,General Materials Science ,Colloids ,Thin film ,Quantum ,Electrodes ,Condensed Matter - Materials Science ,Microscopy, Confocal ,Condensed Matter - Mesoscale and Nanoscale Physics ,business.industry ,Mechanical Engineering ,Photoconductivity ,Bandwidth (signal processing) ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,Condensed Matter Physics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Quantum dot ,Electrode ,Optoelectronics ,business - Abstract
We report on a photodetector in which colloidal quantum-dots directly bridge nanometer-spaced electrodes. Unlike in conventional quantum-dot thin film photodetectors, charge mobility no longer plays a role in our quantum-dot junctions as charge extraction requires only two individual tunnel events. We find an efficient photoconductive gain mechanism with external quantum-efficiencies of 38 electrons-per-photon in combination with response times faster than 300 ns. This compact device-architecture may open up new routes for improved photodetector performance in which efficiency and bandwidth do not go at the cost of one another.
- Published
- 2012
- Full Text
- View/download PDF