Steric-Hindrance-Functionalized Polydiarylfluorenes: Conformational Behavior, Stabilized Blue Electroluminescence, and Efficient Amplified Spontaneous Emission.
ACS applied materials & interfaces 9:43 (2017) 37856-37863
Abstract:
Control of the hierarchical molecular organization of polydiarylfluorenes by synthetic strategies is significant for optimizing photophysical properties as well as the performance of light-emitting devices. Herein, for the suppression of molecular aggregation and enhancement of luminescence efficiency, a series of steric units were introduced into polydiarylfluorenes by copolymerization, with the aim of integrating the advantages of the steric-hindrance effect and of the β-phase. Optical and Raman spectroscopies revealed a β-phase conformation for a polymer copolymerized with spiro[fluorene-9,9'-xanthene] (SFX), with photoluminescence (PL) peaks at 454, 482, and 517 nm. Moreover, the morphological stability and electroluminescence (EL) stability were also improved without compromising the performance of the polymer light-emitting diodes (PLEDs). Furthermore, three steric-hindrance-functionalized copolymers showed significantly decreased thresholds for amplified spontaneous emission (EthASE) and enhanced stability following thermal annealing treatment. These results indicate that steric-hindrance functionalization is a superior approach to improve the overall stability and optoelectronic properties for blue-light-emitting π-conjugated polymers.Thickness Effect of Bulk Heterojunction Layers on the Performance and Stability of Polymer:Fullerene Solar Cells with Alkylthiothiophene-Containing Polymer
ACS SUSTAINABLE CHEMISTRY & ENGINEERING 5:10 (2017) 9263-9270
Polyacetylene-based polyelectrolyte as a universal interfacial layer for efficient inverted polymer solar cells
ORGANIC ELECTRONICS 48 (2017) 61-67
Electron Hopping Across Hemin-Doped Serum Albumin Mats on Centimeter-Length Scales.
Advanced materials (Deerfield Beach, Fla.) 29:27 (2017)
Abstract:
Exploring long-range electron transport across protein assemblies is a central interest in both the fundamental research of biological processes and the emerging field of bioelectronics. This work examines the use of serum-albumin-based freestanding mats as macroscopic electron mediators in bioelectronic devices. In particular, this study focuses on how doping the protein mat with hemin improves charge-transport. It is demonstrated that doping can increase conductivity 40-fold via electron hopping between adjacent hemin molecules, resulting in the highest measured conductance for a protein-based material yet reported, and transport over centimeter length scales. The use of distance-dependent AC impedance and DC current-voltage measurements allows the contribution from electron hopping between adjacent hemin molecules to be isolated. Because the hemin-doped serum albumin mats have both biocompatibility and fabrication simplicity, they should be applicable to a range of bioelectronic devices of varying sizes, configurations, and applications.Thermally stable zinc disalphen macrocycles showing solid-state and aggregation-induced enhanced emission
Inorganic Chemistry American Chemical Society 56:10 (2017) 5688-5695