4 research outputs found
Fast and Efficient Photodetection in Nanoscale Quantum-Dot Junctions
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