Uncooled Infrared Photodetector Utilizing PbSe Nanocrystals

Lead selenide nanocrystals were coupled with the interdigital gold electrodes to create a dissimilar material that is used for detecting near-infrared light at room temperature. The photoluminescence spectrum of the nanocrystals showed a narrow peak at 1.6 μm. A device with 10-μm electrode spacing exhibits excellent photoresponse with an onset at 1.8 μm and detectivity in the order of 3 × 10
⁹
cmHz
^0.5
/W at 5 V bias. The recovery time constant of the device was calculated from the time-resolved photocurrent curve and found to be 0.16 s. The photoresponse spectrum comprises of three distinct peaks in the near-infrared region creating a wavelength selectivity feature.