Fully Solution-Processed ZnO Nanorod Array/PEDOT:PSS Heterojunction Photodetector for Ultraviolet Light

This letter reports an inorganic/organic heterojunction photodetector using n-type zinc oxide nanorod array (NRA) and p-type poly3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT:PSS). ZnO NRA is grown hydrothermally on the ZnO quantum dots (QDs) seed layer deposited on indium tin oxide (ITO) substrate. Further, ZnO NRA is treated with ZnO QDs to get rid of pinholes and PEDOT:PSS is spin-coated over ZnO NRA for the formation of heterojunction. The fully solution-processed ZnO NRA/PEDOT:PSS heterojunction photodetector has a top electrode of printable carbon paste. The ultraviolet (UV) photodetector has shown a maximum responsivity of 9.2 A/W and detectivity of
$7.3\times 10^{{12}}$
cmHz
$^{\text {1/2}}\text{W}^{-{1}}$
under the UV light illumination of
$\boldsymbol {\sim }364$
nm wavelength with a power density of
$102.3~ \boldsymbol {\mu }$
Wcm
⁻²
. Additionally, UV photodetector is highly spectrum selective with promising SNR and faster response.