3 research outputs found
Nanostructured Channel for Improving Emission Efficiency of Hybrid Light-Emitting Field-Effect Transistors
We report on the mechanism of enhancing the luminance and external quantum efficiency (EQE) by developing nanostructured channels in hybrid (organic/inorganic) light-emitting transistors (HLETs) that combine a solution-processed oxide and a polymer heterostructure. The heterostructure comprised two parts: (i) the zinc tin oxide/zinc oxide (ZTO/ZnO), with and without ZnO nanowires (NWs) grown on the top of the ZTO/ZnO stack, as the charge transport layer and (ii) a polymer Super Yellow (SY, also known as PDY-132) layer as the light-emitting layer. Device characterization shows that using NWs significantly improves luminance and EQE (â1.1% @ 5000 cd mâ2) compared to previously reported similar HLET devices that show EQE < 1%. The size and shape of the NWs were controlled through solution concentration and growth time, which also render NWs to have higher crystallinity. Notably, the size of the NWs was found to provide higher escape efficiency for emitted photons while offering lower contact resistance for charge injection, which resulted in the improved optical performance of HLETs. These results represent a significant step forward in enabling efficient and all-solution-processed HLET technology for lighting and display applications
Graphene Oxide: Key to Efficient Charge Extraction and Suppression of Polaronic Transport in Hybrids with Poly (3-hexylthiophene) Nanoparticles
Nanoparticles (NPs)
of conjugated polymers in intimate contact
with sheets of graphene oxide (GO) constitute a promising class of
water-dispersible nanohybrid materials of increased interest for the
design of sustainable and improved optoelectronic thin-film devices,
revealing properties exclusively pre-established upon their liquid-phase
synthesis. In this context, we report for the first time the preparation
of a P3HTNPsâGO nanohybrid employing a miniemulsion
synthesis approach, whereby GO sheets dispersed in the aqueous phase
serve as a surfactant. We show that this process uniquely favors a
quinoid-like conformation of the P3HT chains of the resulting NPs
well located onto individual GO sheets. The accompanied change in
the electronic behavior of these P3HTNPs, consistently
confirmed by the photoluminescence and Raman response of the hybrid
in the liquid and solid states, respectively, as well as by the properties
of the surface potential of isolated individual P3HTNPsâGO nano-objects, facilitates unprecedented charge transfer
interactions between the two constituents. While the electrochemical
performance of nanohybrid films is featured by fast charge transfer
processes, compared to those taking place in pure P3HTNPs films, the loss of electrochromic effects in P3HTNPsâGO
films additionally indicates the unusual suppression of polaronic
charge transport processes typically encountered in P3HT. Thus, the
established interface interactions in the P3HTNPsâGO
hybrid enable a direct and highly efficient charge extraction channel
via GO sheets. These findings are of relevance for the sustainable
design of novel high-performance optoelectronic device structures
based on water-dispersible conjugated polymer nanoparticles
Nanostructured Channel for Improving Emission Efficiency of Hybrid Light-Emitting Field-Effect Transistors
We report on the
mechanism of enhancing the luminance
and external
quantum efficiency (EQE) by developing nanostructured channels in
hybrid (organic/inorganic) light-emitting transistors (HLETs) that
combine a solution-processed oxide and a polymer heterostructure.
The heterostructure comprised two parts: (i) the zinc tin oxide/zinc
oxide (ZTO/ZnO), with and without ZnO nanowires (NWs) grown on the
top of the ZTO/ZnO stack, as the charge transport layer and (ii) a
polymer Super Yellow (SY, also known as PDY-132) layer as the light-emitting
layer. Device characterization shows that using NWs significantly
improves luminance and EQE (â1.1%âŻ@âŻ5000 cd mâ2) compared to previously reported similar HLET devices
that show EQE < 1%. The size and shape of the NWs were controlled
through solution concentration and growth time, which also render
NWs to have higher crystallinity. Notably, the size of the NWs was
found to provide higher escape efficiency for emitted photons while
offering lower contact resistance for charge injection, which resulted
in the improved optical performance of HLETs. These results represent
a significant step forward in enabling efficient and all-solution-processed
HLET technology for lighting and display applications