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Green-processed conjugated materials can reduce the cost of optoelectronic devices and simultaneously minimize their ecological footprint. Here, we use both solution and vapor phase chemistry to oxidatively polymerize the natural hydrocarbon dye, guaiazulene, yielding the more functional material poly(guaiazulene). We chemically characterize oligomers of poly(guaiazulene) using nuclear magnetic resonance spectroscopy, gel-permeation chromatography, laser-desorption ionization mass spectroscopy, and ultraviolet-visible absorption spectroscopy. The optical properties of poly(guaiazulene) oligomers are studied via electronic structure calculations and are contrasted to those of standard poly(azulene). We show that poly(guaiazulene) films synthesized from the vapor phase exhibit enhanced optical properties compared to counterparts synthesized in solution. Collectively, this work outlines a green reaction process that consists of a single step and uses earth-abundant reagents to yield a hitherto unreported polymer for optoelectronic applications. 

Organized nano‐ and microstructures of molecular semiconductors display interesting optical and photonic properties, and enhanced charge carrier mobilities, as compared to disordered thin films. However, known directed‐growth and self‐organization strategies cannot create structured molecular heterojunctions and cannot be practically incorporated into existing device fabrication routines to create large‐area optoelectronic devices. Here, an ultrathin (<2 nm) seed layer of the compound coronene creates 1D nanostructures of an electron‐transporting molecule (IFD) is shown, which possesses an intrinsic proclivity to form disordered thin films in the absence of the seed layer. It is revealed that nanostructured IFD films exhibit enhanced light absorption and emission, and greater electron mobilities, as compared to amorphous counterparts. This seed layer strategy creates uniform IFD nanowires over large areas of up to 18 mm²at low processing temperatures. Notably, the coronene seed layer creates IFD nanowires when applied over either oxide surfaces or predeposited organic layers, meaning that this structuring approach can be integrated into diode manufacturing routines to realize large‐area flexible optoelectronic devices. Flexible organic light‐emitting diodes and fullerene‐free organic solar cells containing IFD nanowires in the photoactive layer to demonstrate that molecular nanostructures can lead to robust, large‐area device arrays on flexible substrates being fabricated.

 

Understanding how dipolar, non-centrosymmetric organic semiconductors self-assemble, nucleate, and crystallize is integral for designing new molecular solids with unique physical properties and light-matter interactions. However, dipole–dipole and van der Waals interactions compete to direct the assembly of these compounds, making it difficult to predict how solids are formed from individual molecules. Here, we investigate four small molecules ( TpCPD , TpDCF , AcCPD , and AcDCF ) possessing anisotropic, non-planar structures and large dipole moments, and establish robust algorithms to control their molecular self-assembly via simple physical vapor deposition. Each molecule contains a central polar moiety, consisting of either a cyclopentadienone (CPD, ca. 3.5 D dipole moment) or dicyanofulvene (DCF, ca. 7.0 D dipole moment) core, that is surrounded by either four twisted phenyl (Tp) groups or a fused aromatic (acenaphthene, Ac) ring system. We find that only molecules containing the fused ring system form 1D nanowires due to the stronger van der Waals associations of the long, planar acenaphthene moieties. We examine the kinetics of self-assembly for AcDCF and create diverse 1D morphologies, including both curved and linear nanostructures. Finally, using conductive AFM (c-AFM) measurements, we show that 1D AcDCF wires support higher current densities relative to randomly-oriented clusters lacking long-range order. 

A facile, solvent-minimized approach to functionalize commercial raw fabrics is described. Reactive vapor deposition of conjugated polymers followed by post-deposition functionalization transforms common, off-the-shelf textiles into distinctly hydrophobic or superhydrophilic materials. The fabric coatings created by reactive vapor deposition are especially resistant to mechanical and solvent washing, as compared to coatings applied by conventional, solution-phase silane chemistries. Janus fabrics with dissimilar wettability on each face are also easily created using a simple, three-step vapor coating process, which cannot be replicated using conventional solution phase functionalization strategies. Hydrophobic fabrics created using reactive vapor deposition and post-deposition functionalization are effective, reusable, large-volume oil–water separators, either under gravity filtration or as immersible absorbants. 

Commercial, untreated cotton fabrics have been directly silver coated using one-step electroless deposition and, subsequently, conformally encapsulated with a thin layer of poly(perfluorodecylacrylate) (PFDA) using initiated chemical vapor deposition (iCVD). The surface of these PFDA encapsulated fabrics are notably water-repellent while still displaying a surface resistance as low as 0.2 Ω cm −1 , making them suitable for incorporation into launderable wearable electronics. X-ray photoelectron spectroscopy confirms that the PFDA encapsulation prevents oxidation of the silver coating, whereas unencapsulated samples display detrimental silver oxidation after a month of air exposure. The wash stability of PFDA-encapsulated, silver-coated cotton is evaluated using accelerated laundering conditions, following established AATCC protocols, and the samples are observed to withstand up to twenty home laundering cycles without notable mechanical degradation of the vapor-deposited PFDA encapsulation. As a proof-of-concept, PFDA-Ag cotton is employed as a top and bottom electrode in a layered, all-fabric triboelectric generator that produces voltage outputs as high as 25 V with small touch actions, such as tapping.