Electrical and optical design and characterisation of regioregular poly(3-hexylthiophene-2,5diyl)/fullerene-based heterojunction polymer solar cells

Electrical and optical properties of poly(3-hexylthiophene-2,5diyl) (P3HT-2,5diyl) used as the main component in a bulk heterojunction polymer/fullerene solar cell were investigated. The HOMO level of the polymer was estimated at about 4.7–5.1 eV, from the observed space charge limited current (SCLC) studies in ITO/P3HT-2,5diyl/Au hole-only devices, which confirmed the formation of ohmic contacts between the polymer and the Au and ITO electrodes. The values calculated for hole mobility and density range from 1.4 × 10-6 cm2/(V s) and 5.3 × 10e14 cm-3 at 150 K to 8.5 × 10-5 cm2/(V s) and 1.1 × 10e15 cm-3 at 250 K, respectively. A HOMO–LUMO gap of 2.14 eV was estimated from an absorption spectrum of the polymer. Photoinduced charge transfer from polymer to PCBM was evidenced by strong photoluminiscence quenching, which was observed when the polymer was mixed with [6,6]-phenyl-C61 butyric acid methyl ester (PCBM). Charge carrier transport properties of the polymer/fullerene solar cells were studied by analysing the dependence of J–V characteristics on temperature and illumination intensity. A linear decrease of the open-circuit voltage with increasing temperature, with a local maximum around 320 K, was observed. The short-circuit current density increased with temperature, having a maximum around 300 K and decreased thereafter. Efficiency and fill factor presented maxima around 3 mW/cm2 white light intensity, and this was attributed to the poor bulk transport properties of the active layer. Typical values recorded for the solar cell at 300 K under white light of 100 mW/cm2 intensity were: open-circuit voltage 0.48 V, and current density 1.28 mA/cm2, with an efficiency of 0.2% and fill factor of 30.6%.

Temperature Dependent Characteristics Of Poly(3 Hexylthiophene)-fullerene Based Heterojunction Organic Solar Cells

Electrical and optical properties of poly(3-hexylthiophene-2.5diyl) (P3HT) used as the main component in a polymer/fullerene solar cell were studied. From the study of space-charge limited current behavior of indium-tin-oxide (ITO)/P3HT/Au hole-only devices, the hole mobility and density were estimated to range from 1.4x10(-6) cm(2)/V s and 5.3x10(14) cm(-3) at 150 K to 8.5x10(-5) cm(2)/V s and 1.1x10(15) cm(-3) at 250 K, respectively. The highest occupied to lowest occupied molecular orbital energetic difference was estimated from absorption spectrometry to be about 2.14 eV. Strong quenching of photoluminescence when the polymer was mixed with [6,6]-phenyl-C(61) butyric acid methyl ester (PCBM), provided evidence of photoinduced charge transfer from P3HT to PCBM. Characterization of ITO/PEDOT:PSS/P3HT:PCBM/Al solar cells was done by analyzing the dependence of current density-voltage characteristics on temperature and illumination intensity. The main solar cell characteristics recorded at 300 K under 100 mW/cm(2) white-light intensity were: Open-circuit voltage 0.48 V, current density 1.28 mA/cm(2), with an efficiency of 0.2%, and fill factor of 30.6%. Open-circuit voltage decreased almost linearly with increasing temperature, while short circuit current density increased with temperature, saturating at around 320 K, and decreased thereafter. Power conversion efficiency and fill factor were maximum around 3 mW/cm(2) due to the poor bulk transport properties of the active layer

Electrical and optical design and characterisation of regioregular poly(3-hexylthiophene-2,5diyl)/fullerene-based heterojunction polymer solar cells

Electrical and optical properties of poly(3-hexylthiophene-2,5diyl) (P3HT-2,5diyl) used as the main component in a bulk heterojunction polymer/fullerene solar cell were investigated. The HOMO level of the polymer was estimated at about 4.7-5.1 eV, from the observed space charge limited current (SCLC) studies in ITO/P3HT-2,5diyl/Au hole-only devices, which confirmed the formation of ohmic contacts between the polymer and the An and ITO electrodes. The values calculated for hole mobility and density range from 1.4 x 10(-6) cm(2)/(V s) and 5.3 x 10(14) cm(-3) at 150 K to 8.5 x 10(-5) cm(2)/(V s) and 1.1 X 10(15) cm(-3) at 250 K, respectively. A HOMO-LUMO gap of 2.14 eV was estimated from an absorption spectrum of the polymer. Photoinduced charge transfer from polymer to PCBM was evidenced by strong photolummiscence quenching. which was observed when the polymer was mixed with [6,6]-phenyl-C-61 butyric acid methyl ester (PCBM). Charge carrier transport properties of the polymer/fullerene solar cells were studied by analysing the dependence of J-V characteristics on temperature and illumination intensity. A linear decrease of the open-circuit voltage with increasing temperature, with a local maximum around 320 K, was observed. The short-circuit current density increased with temperature, having a maximum around 300 K and decreased thereafter. Efficiency and fill factor presented maxima around 3 mW/cm(2) white light intensity, and this was attributed to the poor bulk transport properties of the active layer. Typical values recorded for the solar cell at 300 K under white light of 100 mW/cm2 intensity were: 2 open-circuit voltage 0.48 V, and current density 1.28 mA/cm(2), with an efficiency of 0.2% and fill factor of 30.6%. (C) 2003 Elsevier Science B.V. All rights reserved

Electronic properties of polymer-fullerene solar cells studied with light-induced electron spin resonance and admittance spectroscopy

Within recent years, the development of polymer-fullerene plastic solar cells has made significant progress. In such devices, an efficient charge generation takes place via photoinduced charge transfer between the photoexcited conjugated polymer and acceptor-type fullerene molecules. Due to the paramagnetic nature of the radical species, the photoinduced charge transfer can be studied by means of light induced electron spin resonance (LESR) techniques. We carried out W-band (95 GHz) LESR at high magnetic field strengths. Two well separated line groups with a strong anisotropic structure were detected for the composite MDMO-PPV:PCBM. From the line shape analysis, we obtained an environmental axial symmetry for the positive polaron P+ and a lower, rhomboedric symmetry for the fullerene anion. The signals were found to be independent of each other with different spin-lattice relaxation times; hence, the radical species can be investigated separately. In order to study the bulk transport properties, we carried out admittance spectroscopy on the ITO/PEDOT:PSS/MDMO-PPV:PCBM/Al device. Two frequency-dependent contributions to the device capacitance with the activation energies 9 meV and 177 meV were found. For the very shallow trap state, we assume a bulk impurity, whereas the latter one is assigned to an interracial defect state, located at the composite-aluminium interface

Influence of fillers concentration on electrical properties of polystyrene matrix doped by gold nanoparticles and 8HQ

34.70.+e Charge transfer, 77.80.Fm Switching phenomena, 91.60.Tn Transport properties, 82.35.Np Nanoparticles in polymers,