Letter abstract
Nature Photonics 3, 332 - 336 (2009)
Published online: 17 May 2009 | doi:10.1038/nphoton.2009.72
Subject Categories: Imaging and sensing | Optoelectronic devices and components
Near-infrared imaging with quantum-dot-sensitized organic photodiodes
Tobias Rauch1,6, Michaela Böberl2,5,6, Sandro F. Tedde1, Jens Fürst1,5, Maksym V. Kovalenko3, Günter Hesser2, Uli Lemmer4, Wolfgang Heiss3 & Oliver Hayden1
Abstract
Solution-processed photodiodes with infrared sensitivities at wavelengths beyond the bandgap of silicon (corresponding to a wavelength of 
1,100 nm) would be a significant advance towards cost-effective imaging. Colloidal quantum dots are highly suitable as infrared absorbers for photodetection, but high quantum yields have only been reported with photoconductors1, 2, 3. For imaging, photodiodes are required to ensure low-power operation and compatibility to active matrix backplanes4. Organic bulk heterojunctions5 are attractive as solution-processable diodes, but are limited to use in the visible spectrum. Here, we report the fabrication and application of hybrid bulk heterojunction photodiodes containing PbS nanocrystalline quantum dots as sensitizers for near-infrared detection up to 1.8 
m, with rectification ratios of 6,000, minimum lifetimes of one year and external quantum efficiencies of up to 51%. By integration of the solution-processed devices on amorphous silicon active matrix backplanes, we demonstrate for the first time near-infrared imaging with organic/inorganic hybrid photodiodes.
- Siemens AG, Corporate Technology, CT MM1, 91058 Erlangen, Germany
- Christian Doppler Laboratory for Surface Optics, Institute of Semiconductor and Solid State Physics, University of Linz, 4040 Linz, Austria
- Institute of Semiconductor and Solid State Physics, University of Linz, 4040 Linz, Austria
- Light Technology Institute, Universität Karlsruhe (TH), 76128 Karlsruhe, Germany
- Present address: Siemens VAI MT GmbH & Co, I IS MT IR AG T, 4031 Linz, Austria (M.B.); Siemens AG, H IM CVV, 91058 Erlangen, Germany (J.F.)
- These authors contributed equally to this work
Correspondence to: Tobias Rauch1,6 e-mail: tobias.rauch.ext@siemens.com
Correspondence to: Oliver Hayden1 e-mail: oliver.hayden@siemens.com
