Integrating an electrically active colloidal quantum dot photodiode with a graphene phototransistor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27311710.
- Also identified by DOI 10.1038/ncomms11954 and PMC identifier 4915030.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The realization of low-cost photodetectors with high sensitivity, high quantum efficiency, high gain and fast photoresponse in the visible and short-wave infrared remains one of the challenges in optoelectronics. Two classes of photodetectors that have been developed are photodiodes and phototransistors, each of them with specific drawbacks. Here we merge both types into a hybrid photodetector device by integrating a colloidal quantum dot photodiode atop a graphene phototransistor. Our hybrid detector overcomes the limitations of a phototransistor in terms of speed, quantum efficiency and linear dynamic range. We report quantum efficiencies in excess of 70%, gain of 10(5) and linear dynamic range of 110 dB and 3 dB bandwidth of 1.5 kHz. This constitutes a demonstration of an optoelectronically active device integrated directly atop graphene and paves the way towards a generation of flexible highly performing hybrid two-dimensional (2D)/0D optoelectronics.