Bimolecular charge carrier recombination has been clarified in bulk-heterojunction solar cells based on a blend of regioregular poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene using the time-of-flight method. We show how bimolecular influences transport, it limits efficiency low-mobility cells, to estimate coefficient. found that these efficient photovoltaic materials is orders magnitude slower as compared Langevin expected for materials. This effect...

Thin-film field-effect transistors (FETs) have been prepared using poly(3-hexylthiophene)/ arachidic acid and quinquethiophene/arachidic Langmuir–Blodgett (LB) films with thicknesses ranging from a monolayer to some ten monolayers. The effect of the number layers on mobility conductivity has studied. This is our knowledge first demonstration LB FET utilizing organic semiconductors as active material.

The transport properties, namely mobility, conductivity, and charge carrier concentration of three model polymers, regioregular poly(3-hexylthiophene) (RRPHT), poly(p-phenylene vinylene) (PPV), a polyazomethine (PAM) are investigated by extraction in linearly increasing voltage. We have numerically modeled the transients including Gaussian distribution localized states typical Poole-Frenkel-type field-dependent mobility observed these materials, good agreement with measured values is...

The dependence of the d.c. conductivity on hydration and temperature (293-343 K) for synthetic DOPA-melanin polymer is presented. state melanin has been changed by varying humidity conditions around sample. It shown, that in range relative values (0-100%), changes have predominant influence electrical (10-13-10 -5S cm-1) comparison to temperature. two forms water conductivity-the first form adsorbed mainly surface easily removed drying, second one incorporated into inner structure polymer,...

The results of an experimental study dc and microwave electrical conductivities, electron-spin resonance, optical reflection, infrared absorption in ${\mathrm{FeCl}}_{3}$-doped polyparaphenylene (PPP) are presented. In low-conducting PPP, the conductivity is described by interpolaron hopping processes among polaron bipolaron states induced doping. Further evidence for these obtained from ir ESR doped PPP. new modes due to doping behavior spin density as a function dopant concentration can be...

An organic transistor is presented, showing a one-hundred-fold increase in current level at operating voltages around 1 V and excellent modulation (see Figure) resulting from the ionic effects present hygroscopic insulator when operated ambient atmosphere.

We report the observation of photoluminescence quenching in thin films poly(3-hexylthiophene) and Langmuir–Blodgett poly(3-hexylthiophene)/arachidic acid by injection positive charges polymer. Charge was made a polymer field effect transistor, used what we name luministor mode. The is discussed terms polarons/bipolarons acting as recombination centra for excitons, suppressing photoluminescence. inverse phenomenon, luminescence enhancement depletion charges, has also been achieved.

We have studied photogenerated charge carrier transport and recombination in thick films of regiorandom poly(3-hexylthiophene) by using the current mode time-of-flight technique. measured extracted as a function light intensity applied voltage, found that for $\ensuremath{\alpha}d⪢1$ it saturates at value can be stored on contacts ${Q}_{e}=C{U}_{0}$ expected diffusion controlled bimolecular recombination, i.e., Langevin recombination. As consequence we only measure space perturbed...

Polarized electroluminescence (EL) from an oriented poly(3‐alkylthiophene) structure is reported, which a first step towards the fabrication of organic light‐emitting diode (LED) that emits polarized light. A multilayer described includes Langmuir‐Blodgett film poly(3‐decylmethoxythiophene), PDMT, in polyenic backbones are along dipping direction. The optical properties–absorption, EL, photoluminescence –and I – V curve for ITO/PDMT/Al device presented.

In low-mobility materials the charge carrier mobility is usually measured using time-of-flight (TOF) methods. However, use of TOF methods calls for a necessary condition to be fulfilled: viz., that dielectric relaxation time must bigger than transit time, ${\ensuremath{\tau}}_{\ensuremath{\sigma}}\ensuremath{\gg}{t}_{\mathrm{tr}},$ through interelectrode distance d. If this not fulfilled, then equilibrium concentration ${p}_{0}$ sufficient redistribute electric field inside sample during...

The operating principle of a hygroscopic insulator field-effect transistor has been investigated. semiconductor poly(3-hexylthiophene) shows an increased conductivity after applying the poly(vinylphenol) (PVP) insulator, which is attributed to interfacial dipole layer caused by permanent moment in PVP. effects solvents on device indicate that low molecular weight protic such as water, methanol, and ethanol affect I-V characteristics significantly, contrast 1-propanol aprotic acetonitrile....

We have measured the recombination dynamics of long-lived polarons in two regioregular poly(3-alkylthiophenes) (RR-PATs) using cw- and transient (in ms time regime) photoinduced absorption (PA). find that millisecond regime can be fitted with a combination one (fast) hyperbolic decay component (slow) modified hyperbolic. The fast is almost temperature independent at low temperatures, while slow shows an exponential dependence whole range. modeled PA bimolecular continuum band, including...

Thermochromism and optical absorption in mono- multilayers of Langmuir–Blodgett films poly(3-alkylthiophenes), poly(3-octyl-2,2′-bithiophene), poly(3′-octyl-2,2′;5′,2″-terthiophene) were studied. In sparsely alkylated polythiophenes the magnitude thermochromic shift was smaller than poly(3-alkylthiophenes) roughly proportional to sidechain concentration. Results Valence Effective Hamiltonian calculations compared with experimental results thermochromism. A vibronic structure found spectra at...

Abstract The results of an experimental study the temperature ( T ) dependent dc conductivity σ , ‐dependent thermoelectric power (TEP), and electron spin resonance in a new conducting polyethylenevinylacetate–polyoctylthiophene (EVAPOT) polymer blend doped with FeCl 3 are presented. For POT content 20 wt% (300 K) varies from 10 −10 to 1 Ω −1 cm increasing doping, while fits = 0 exp [– / 1/2 ], especially highly material. In most heavily samples TEP shows metallic behaviour charge transport...

Transient characteristics of organic light-emitting diodes with Langmuir–Blodgett films quinquethiophene as the emitting material have been studied. Field and thickness dependence response time From lag between voltage pulse first appearance electroluminescence emission, mobility parallel to chain molecules has calculated. In thicker films, anisotropy in observed when compared previous results obtained from field-effect studies. The interfaces found play an important role thinner films.