Facile Fabrication of PbS Nanocrystal:C60 Fullerite Broadband Photodetectors with High Detectivity

• DOI: 10.1002/adfm.201202818
• Publication Date: 2013-03-13T02:04:07Z
• Authors: Rinku Saran; Muhammad N. Nordin; Richard J. Curry
• Keywords: PbS nanocrystals; charge transfer; photodetectors; C fullerites; 02 engineering and technology; 0210 nano-technology; 7. Clean energy

AbstractHybrid PbS nanocrystal/C60 fullerite photodetectors are fabricated using a simple one‐step drop casting procedure onto pre‐patterned interdigitated electrodes. The devices exhibit a broad spectral response from the near UV through to the near infrared yielding a detectivity, D*, of above 1010 Jones from 400 nm to ≈1050 nm. The ability to further extend the spectral response to wavelengths ≈1350 nm in the near infrared via tuning of the PbS nanocrystal diameter is also demonstrated. The dynamic responses of the devices are presented, exhibiting a fast photocurrent rise time (<40 ns) followed by a long bi‐exponential decay with characteristic lifetimes of τ1 = 5.3 μs ± 0.1 μs and τ2 = 37.8 μs ± 0.7 μs. These devices, which have a detectivity approaching that of commercial detectors, a broader spectral response, and a fast rise time, offer an attractive low‐cost solution for large‐area broadband photodetectors.