Colloidal quantum dots based infrared photodiodes

Jian Xu, Dehu Cui, Shengyong Xu, Gary Paradee, Michael Gerhold

Research output: Contribution to journalConference articlepeer-review


We report in this paper our studies on the photoconductivity and photovoltaic effects of colloidal PbSe nanocrystal quantum dots (NQDs) which were embedded in conductive polymer matrices to form hybrid polymer/NQD infrared photodiodes. The generation of photocarriers in PbSe NQDs and their transport in NQD-polymer composites were described by a simplified band diagram picture of the device. Both photocurrent and photovoltage outputs were measured from the NQD-incorporated photodiode upon the illumination of near-infrared (NIR) light, whereas the net polymer-based devices do not exhibit any photoresponsivity. The intensity dependence of the photocurrent indicates the pseudomonomolecular recombination kinetics in the NQD-polymer composite. The measured photocurrent spectrum is consistent with the absorption characteristic of PbSe NQDs, Further enhancement of the photodiode efficiency can be achieved by engineering the nanocrystal surface to reduce the potential barriers due to the ligant capping molecules. copyright The Electrochemical Society.

Original languageEnglish (US)
Pages (from-to)17-31
Number of pages15
JournalECS Transactions
Issue number33
StatePublished - Dec 1 2006
EventPhotoboltaics for the 21st Century III - 208th Electrochemical Society Meeting - Los Angeles, CA, United States
Duration: Oct 16 2005Oct 21 2005

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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