Solution Processed ITO/ZnO QDs/TIPS -Pentacene/MoOₓ High-Performance UV-Visible Photodetector

This letter reports a TIPS-Pentacene (TIPS-P) based ultraviolet-visible (UV-Vis) photodetector using zinc oxide (ZnO) colloidal quantum dots (CQD) (of an average size of ~2.00 nm) layer as the electron transport layer (ETL)-cum-UV absorption region and a MoO
_x
layer for the hole transport layer (HTL). The overall device structure is ITO/ZnO CQDs/TIPS-P/ MoO
_x
/Ag where indium tin oxide (ITO)-coated glass is the substrate and Ag is the anode contact of the device. ZnO CQDs and TIPS-P layers are grown by spin coating method while the MoOx layer and Ag contact electrode are grown by thermal evaporation method. Under −1 V reverse bias voltage, the photoresponse of the proposed device gives the maximum responsivity (R) of ~217.24 A/W, detectivity (D) of
${\sim }6.79 \times 10^{12}$
cmHz
$^{1/2}$
/W and external quantum efficiency (EQE) of 69811.93 % at 386 nm incident light of
$46 ~\mu \text{W}$
/cm
²
intensity while R~57.34 A/W,
$D \sim 1.79 \times 10^{1}$
cmHz
$^{1/2}$
/W and EQE ~11111.3 % were obtained at 640 nm incident light of
$48.8 ~\mu \text{W}$
/cm
²
intensity.