Application of 2D-MoO₃ nano-flakes in organic light emitting diodes: effect of semiconductor to metal transition with irradiation

Abstract

The current work demonstrates efficient utilization of 2D-MoO 3 nano-flakes as a hole injection layer (HIL) in organic light emitting diodes (OLEDs). Nano-flakes are synthesized using an organic solvent-assisted grinding and sonication method of liquid exfoliation for MoO 3 , and 8-16 nm thick flakes are obtained. The effect of solar illumination on the hole injection properties of these nano-flakes is then studied by exposing the nano-flakes for 0, 15, 30, 45, 60 and 120 min and using them as HIL in green OLED. The device results are then compared with the OLED having bulk MoO 3 as HIL. OLEDs with nano-flakes as the HIL have shown better performance than the OLED with bulk MoO 3 as the HIL due to the better semiconducting properties in the nano-flake phase. The luminous intensity is increased by increasing the duration of irradiation and was found to be optimum in case of nano-flakes irradiated for 30 or 45 min and then started to decrease with the increase of duration of irradiation. The current density in the OLEDs with nano-flakes as the HIL shows a switching from high resistance to low resistance; however, the sequential pattern of switching voltage was missing with the duration of irradiation. The current density also decreased for nano-flakes with 60 and 120 min of irradiation. Transition from the semiconducting to metal nature of nano-flakes by solar irradiation is suggested to be the reason behind this decrease in current density and luminous intensity with a longer duration of illumination.

Coating ZnO nanoparticle films with DNA nanolayers for enhancing the electron extracting properties and performance of polymer solar cells

“…as donor polymer and PC70BM [ [6,6]-Phenyl-C70-butyric acid methyl ester] as acceptor 8,19,20 . The hole extraction layer consisted of MoO3 layer 20,21 . We used ZnO-NPs dispersion which is commercially available 22 .…”

Facile and low cost oxidative conversion of MoS2 in α-MoO3: Synthesis, characterization and application

“…Due to its high hole mobility, good environmental stability and electronic properties, the MoO3 is a promising and highly attractive candidate to replace the poly3,4-ethylene dioxythiophene: polystyrene sulphonic acid (PEDOT:PSS) in organic solar cells [6,9] and other electronic devices [10]. The most employed material as hole transportation layer (HTL) for organic solar cells is PEDOT:PSS which, in general, needs to be doped [6].…”

Characterization of hierarchicalα-MoO3plates toward resistive heating synthesis: electrochemical activity ofα-MoO3/Pt modified electrode toward methanol oxidation at neutral pH

“…α-MoO 3 phase is known to develop into different objects with controlled shape and size, such as rods [22][23][24], ribbons [25], belts [8,12,20,26], fibers [27,28], flakes [29,30], whiskers [31,32], nanotubes [33,34], sheets [4,11,33] and wires of micrometer or nanometer diameters [35,36]. However, regarding the synthesis of hierarchical and complex MoO 3 nanostructures, only a limited number of papers have been published.…”