Ester units make conjugated polymers easier to break down and rebuild, but can also interrupt charge transport. This study compares physical blending with terpolymerization as routes to recover transistor performance. Adding 10 wt% of a fully conjugated polymer to ester-containing DPP polymers gives substantially greater mobility improvements than distributing comparable conjugated segments chemically along the backbone.
This review follows how water uptake in PSS-rich regions changes PEDOT:PSS film structure, disrupts conducting pathways, and weakens adhesion. It compares solvent treatments, surfactants, crosslinking, and modification of PSS as stabilization approaches, with attention to the trade-offs among conductivity, mechanical properties, and water resistance.
Layer-by-layer solution processing of PTB7-Th and COTIC-4Cl inverted organic photodetectors increases crystallinity and lowers trap density, which reduces recombination and improves photoresponsivity. Adding the wide-bandgap polymer PVK shifts the trap distribution from shallow to deeper levels and suppresses charge injection under reverse bias, lowering dark current. The devices reach a specific detectivity above 10¹² Jones at 1050 nm under −0.2 V bias.
A siloxane hybrid dielectric combines polar groups in the film bulk with a fluorinated surface. The bulk promotes dielectric polarization, while the surface limits moisture-related trapping at the semiconductor interface. This separation of bulk and interface functions supports stable transistor operation at low voltage.
Carrier–dopant attraction is examined separately from carrier mobility in doped P3HT films. Larger dopants favor free-carrier generation at low doping levels by weakening Coulomb binding. At higher doping levels, overlapping Coulomb potentials reduce the dissociation barrier, allowing smaller dopants to support higher carrier densities. Dopant selection therefore depends on the intended doping regime.
A dual-additive approach separates control of acceptor crystallinity from control of molecular orientation. Dibenzofuran promotes ordering, while halogenated naphthalene modifies the packing orientation. In PM6:L8-BO solar cells, this combination improves charge transport and produces a reported power conversion efficiency of 19.58%.
This study identifies the chemical and structural origin of p-to-n polarity switching in a heavily doped conjugated polymer, using gold(III) chloride-doped IDTBT as a model system. Quantitative X-ray photoelectron spectroscopy shows oxidation-state changes in Au and Cl and covalent chlorination of the polymer backbone, which ties the doping chemistry directly to the polarity change. The switching behavior is then used to build a p-n homojunction organic diode with a rectification ratio of 10⁴ to 10⁵.
Plasticizing molecular additives are used to tune the persistence length of the rigid conjugated polymer PDPP2T-TT-OD without modifying its backbone chemistry. Solution small-angle neutron scattering links each additive to changes in chain rigidity, and film measurements show that the mechanical modulus follows persistence length and the formation of uniformly entangled networks with smaller crystalline grains. The blended films become more deformable while charge mobility remains stable after stretching to 100% strain.
The study examines how polymer crystallinity affects dopant penetration during sequential solution doping. More crystalline films contain a larger dopant fraction near the surface and a less uniform depth profile. Their reduced swelling limits diffusion into the film interior, connecting polymer structure to the spatial distribution of dopants.
Changing the donor unit in DPP-based polymers tunes backbone rigidity and the response to stretching. DPP-4T has a shorter solution persistence length than DPP-DTT and combines greater deformability with enhanced hole transport under strain. Scattering and spectroscopic measurements connect this improvement to chain alignment and backbone planarization; DPP-4T shows a 180% mobility increase at 80% strain.
This study examines how tensile strain affects the bias-stress stability of stretchable polymer field-effect transistors. Structural analysis of stretched films and spectroscopic quantification of trapped charge show that larger strain introduces cracks and nanoscale cavities that raise water content and reduce stability. Passivating the devices against water penetration removes the strain dependence of bias-stress stability.
Photoaging can change an acceptor’s molecular conformation and quench its luminescence, increasing nonradiative voltage losses in organic solar cells. This study shows that introducing a third component with more stable luminescence can reduce the initial burn-in loss. Its distribution within the mixed phase is important to the stabilization effect.
This review connects molecular conformation, thin-film morphology, and larger-scale mechanical deformation to charge transport in stretchable conjugated polymers. It introduces mechanical testing methods and compares approaches including functional additives, crosslinking, and polymer nanowires for balancing electrical performance with stretchability.
Photocrosslinking provides a way to regulate anion motion in conjugated polymers. The study uses this control of ion transport to improve the linear response and retention of organic artificial synapses.
This work proposes direct protonation of organic semiconductors by water as an origin of bias-stress trap generation in organic field-effect transistors. Spectroscopic and electrical measurements combined with simulations show that this process is independent of trap generation at the insulator surface. The same behavior appears in small-bandgap polymers with fused thiophene rings regardless of crystalline order, suggesting a general mechanism in this class of polymer semiconductors.
This study compares azide photocrosslinkers with different ethylene glycol spacer lengths in semicrystalline and nearly amorphous conjugated polymers. The shortest crosslinker most effectively improves the stretchability of IDTBT films. The results point to the importance of crosslink density within amorphous regions, rather than assuming that a longer, more flexible crosslinker will always produce a more stretchable film.
The effect of FeCl₃ doping on charge transport is compared in ordered DPPDTT and more disordered IDTBT films. DPPDTT shows a strong mobility increase under heavy doping, whereas IDTBT changes little. The different responses link the initial molecular arrangement to the balance between coherent and incoherent transport, showing why increasing carrier density alone does not determine conductivity.
Earlier reports disagreed on whether small-molecule acceptors stabilize or destabilize polymer donors. Comparing PTB7:PCBM blends with contrasting acceptor morphologies shows that PCBM dispersed in a mixed phase drives triplet-mediated singlet oxygen generation and severe photooxidation of PTB7, whereas aggregated PCBM stabilizes the polymer. Photooxidation destroys crystalline PTB7 domains and degrades hole transport in step with solar cell efficiency losses, and the same trend holds for the nonfullerene blends PTB7:ITIC and PTB7:Y6.
Gap-controlled bar coating is used to produce patterned organic semiconductor films with highly ordered crystalline domains. Adjusting coating conditions and solvent additives controls nucleation, fluid flow, and vertical phase separation. The resulting transistor arrays reach a field-effect mobility of up to 20 cm² V⁻¹ s⁻¹, illustrating how solution flow can connect scalable processing with electronic performance.
A pentacene/Alq₃ bilayer forms the active and charge-storage regions of an organic transistor memory. Sequential deposition creates a heterointerface whose energy-level offset controls charge transfer during writing and erasing. The devices demonstrate nonvolatile memory operation with stability in air.
This review examines why organic transistors lose stability during prolonged electrical bias. It connects charge-trapping measurements with the roles of semiconductor layers, gate insulators, and electrical contacts, then discusses materials and interface strategies for reducing bias-stress degradation.