In an attempt to overcome the technical challenges in the conventional solution-processed near infrared (NIR) photodetectors, we have used NaY F4: Yb, Er upconversion fluorescence nanocrystals to replace the semiconductor quantum dots in conjugated polymers. Under NIR excitation, the NaY F4: Yb, Er nanocrystals emit visible light in the solution-processed NIR photodetectors. The emitted visible light is simultaneously absorbed by the host conjugated polymer to generate photocurrent, which indicates that our approach is applicable to fabricate NIR photodetectors while avoiding the major technical challenges associated with semiconductor quantum dot based NIR photodetectors.
Bibliographical noteFunding Information:
This research is sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC for the US Department of Energy under Contract No. DEAC05-00OR22725.