Harnessing the omnipresent radio frequency (RF) waves intend to explore the new diode technologies as they determine the frequency of operation and ultimately the power conversion efficiency. Recently, a considerable effort focused on performance, reliable and low-cost fabrication methods. Here, we report the fabrication of sub-20 nm co-planar, asymmetric and self-forming nanogap electrodes by adhesion lithography (a-Lith) as an alternative, low-cost and large-area patterning technique. Moreover, solution processing and rapid Flash Lamp Annealing (FLA) route employed to fabricate Schottky diodes. These diodes are having more than 104 On/Off ratio, low series resistance and junction capacitance due to the novel co-planar architecture and thus operating beyond 10 GHz. This paves the way to a radically new diode technology that has a huge impact on the IoT – Wireless Energy Harvesting (WEH) and RFID system.
We present the synthesis and characterization of four conjugated polymers containing a novel chromophore for organic electronics based on an indigoid structure. These polymers exhibit extremely small band gaps of ∼1.2 eV, impressive crystallinity, and extremely high n-type mobility exceeding 3 cm2 V s–1. The n-type charge carrier mobility can be correlated with the remarkably high crystallinity along the polymer backbone having a correlation length in excess of 20 nm. Theoretical analysis reveals that the novel polymers have highly rigid nonplanar geometries demonstrating that backbone planarity is not a prerequisite for either narrow band gap materials or ultrahigh mobilities. Furthermore, the variation in backbone crystallinity is dependent on the choice of comonomer. We find that electron mobility can be correlated to the degree of order along the conjugated polymer backbone. Finally, we use this novel system to begin to understand the complicated effect of alkyl chain variation on the solid state packing in all 3 dimensions.
Plastic electronics that can be manufactured using solution-based methods are the subject of great research interest due to their potential for low-cost, large-area electronic applications. The interest in this field has led to considerable research and subsequent advances in device performance. To this end solution-processed organic thin-film transistors (OTFTs) have shown impressive improvements in recent years through the increasing values of charge carrier mobility. Here we report the development of next generation organic blend materials for OTFTs with hole mobilities of 10 cm2/Vs. These high performance devices have been achieved using a novel semiconducting blend system comprising of an amorphous-like conjugated polymer and a high mobility small molecule. The combination of a highly crystalline small molecule with the polymer binder aids the formation of uniform films as well as enables an element of control over the nucleation and growth of the small molecule. The polymer binders investigated belongs to the family of indacenodithiophene-based copolymers which are renowned for their high carrier mobilities regardless of their apparent structural disorder. The addition of the polymer with carefully chosen small molecules is found to further increase the hole mobility of the resulting blend OTFT to over 10 cm2/Vs. These organic devices provide an interesting insight into this rather complex blend system, highlighting the correlation between the morphology developed following solution processing and device performance, as well as exploring the role of each of the two components in the blend in terms of their contribution to charge transport.
Novel, extremely narrow band-gap polymer with a structure based on natural indigo has been synthesised and exhibits high crystallinity, high ambipolar transport in OFET devices, and OPV device efficiencies up to 2.35% with light absorbance up to 950 nm, demonstrating potential in near-IR photovoltaics. We demonstrate that the use of a potentially bio-sustainable monomer unit in a conjugated polymer can give balanced ambipolar OFET mobilities in excess of 0.5 cm2/Vs. This novel monomer, and polymers are synthesized by rigidifying the structure of indigo by condensation with an aromatic acidic acid. The materials display high crystallinity which can be further enhanced by annealing and demonstrate that it can be used as a potentially biosustainable alternative to the commonly used DPP and iso-indigo monomers. We believe this is the first attempt to tackle the issue of sustainability in conjugated polymer synthesis.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print format on
SPIE.org.