Abstract:
A low-cost photoconductive dual-band detector
based on a ZnO film sensitized with lead sulfide quantum dots
(PbS-QDs) is reported. The UV response arises from the interband
absorption of UV radiation by ZnO, and the IR response is due to
the absorption in the PbS-QDs. The detector exhibits UV response
from 200 to 400 nm with a peak responsivity of 4.0 × 105 V/W and
detectivityD∗ of 5.5 × 1011 Jones at 370 nm at room temperature.
The observed visible–near IR response is from 500 to 1400 nm with
a responsivity of 5.4 × 105 V/W and D∗ of 7.3 × 1011 Jones at
700 nm operating at room temperature. By increasing the PbS-QD
size, the IR response can extend up to 2.9 μm.
