In this work, different steps involved in the fabrication of polymer solar cells were optimized using P3HT/PCBM heterojunction. Steps included spinning speed for coating of the PEDOT:PSS layer, use of filter for the PEDOT:PSS layer, spinning speed for coating of the active layer, sequence of annealing of the active layer either before or after electrode deposition, and modification of the cooling mechanism (either by cooling rapidly or slowly after heating of the active layer). Investigation of these steps led to an improvement of the power-conversion efficiency (PCE) of the polymer solar cells, especially the last step involving the change of cooling mechanism, which improved PCE by 25%. 相似文献
Spin‐coating a mixture solution of P3HT and PCBM on a cold substrate largely enhanced the power conversion efficiency (PCE) of the bulk heterojunction (BHJ) solar cells. This concept was based on the abrupt decrease in the solubility of P3HT as solution temperature decreased. The selective precipitation of P3HT on the PEDOT:PSS‐coated cold substrate facilitated a desirable rich composition of P3HT at the interface with the PEDOT:PSS layer. The high crystallinity of P3HT suppressed the movement of PCBM during thermal annealing, preventing aggregation of PCBM. The morphological excellence of the pristine film gave a comparable PCE to that made by the conventional fabrication process. After thermal annealing, the device made via coating on a cold substrate showed above 30% increase in PCE from the BHJ solar cells made by the conventional method.
Indium tin oxide (ITO) is used as a substrate was covered with 4-[4-(4-methoxy-N-naphthalen-2-ylanilino) phenyl] benzoic acid (MNA) as a self-assembled monolayer (SAM). Poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6) C61 (PCBM) were mixed and used as a donor–acceptor in organic solar cell (OSC). The MNA (SAM) layer is used as an interface instead of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) for hole injection. The HOMO-LUMO energy level of MNA-SAM molecule and the electronic charge distribution were calculated theoretically using Chemissian software. The HOMO-LUMO energy level of the MNA is calculated as EHOMO = ?5.10 eV and ELUMO = ?1.60 eV. The OSC modified with MNA showed an efficient performance in the absence of PEDOT: PSS as hole transport layer. The annealing of the ITO/SAM/P3HT: PCBM films at different temperatures are also investigated to study the effect of reducing defects. The interface structures of the organic semiconductor layer on ITO were characterized by Atomic Force Microcopy (AFM). In addition, Kelvin Probe Microscopy (KPM) is used to understand how the annealing changes the surface potential energy of the ITO/SAM substrate. Using the KPM method, which measures the surface potential energy of the films, the energy bands of the ITO were increased to maximum 5.09 eV. The ITO/SAM/P3HT: PCBM film's surface potential was determined to be 0.18 eV after being annealed at 80 °C. The surface potential of the modified films was discovered to be 0.33 V and 0.39 V when the annealing temperature was raised from 80 °C to 120 °C and 160 °C. The maximum device efficiency was demonstrated by the ITO/SAM/P3HT: PCBM film after an hour of annealing at 160 °C. 相似文献
In this study, polymeric nanocomposites of poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) and functionalized multi-walled carbon nanotubes (MWCNTs) were spin coated on a pre-patterned ITO glass and used as a hole conducting layer in organic photovoltaic cells. The multi-layered ITO/MWCNT-PEDOT:PSS/CuPc/C60/Al devices were fabricated to investigate the current density-voltage characteristics and power conversion efficiency. The power conversion efficiency obtained from the device with a concentration of 1.0 wt% MWCNT in the PEDOT:PSS layer was increased twice as those adopted from device without MWCNT doping in the PEDOT:PSS layer and current density-voltage characteristics was also improved well with incorporation of MWCNTs. 相似文献
3-Hydroxy-1-propanesulfonic acid(HPSA)was applied as a modification layer on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)film via spin-coating,resulting in a massive boost of the conductivity of PEDOT:PSS film,and thus the as-formed PEDOT:PSS/HPSA bilayer film was successfully used as a transparent electrode for ITO-free polymer solar cells(PSCs).Under the optimized concentration of HPSA(0.2 mol L~(-1)),the PEDOT:PSS/HPSA bilayer film has a conductivity of 1020 S cm~(-1),which is improved by about 1400 times of the pristine PEDOT:PSS film(0.7 S cm~(-1)).The sheet resistance of the PEDOT:PSS/HPSA bilayer film was 98Ωsq~(-1),and its transparency in the visible range was over 80%.Both parameters are comparable to those of ITO,enabling its suitability as the transparent electrode.According to atomic force microscopy(AFM),UV-Vis and Raman spectroscopic measurements,the conductivity enhancement was resulted from the removal of PSS moiety by methanol solvent and HPSA-induced segregation of insulating PSS chains along with the conformation transition of the conductive PEDOT chains within PEDOT:PSS.Upon applying PEDOT:PSS/HPSA bilayer film as the transparent electrode substituting ITO,the ITO-free polymer solar cells(PSCs)based on poly[N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)]:[6,6]-phenyl C71-butyric acid methyl ester(PC_(71)BM)(PCDTBT:PC_(71)BM)active layer exhibited a power conversion efficiency(PCE)of 5.52%,which is comparable to that of the traditional ITO-based devices. 相似文献
The spatial distribution of reaction products in multilayer polymer solar cells induced by water and oxygen atmospheres was mapped and used to elucidate the degradation patterns and failure mechanisms in an inverted polymer solar cell. The active material comprised a bulk heterojunction formed by poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) sandwiched between a layer of zinc oxide and a layer of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) that acted as, respectively, electron and hole transporting layers between the active material and the two electrodes indium-tin-oxide (ITO) and printed silver. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) in conjunction with isotopic labeling using H(2)(18)O and (18)O(2) enabled detailed information on where and to what extent uptake took place. A comparison was made between the use of a humid (oxygen-free) atmosphere and a dry oxygen atmosphere during testing of devices that were kept in the dark and devices that were subjected to illumination under simulated sunlight. It was found that the reactions taking place at the interface between the active layer and the PEDOT:PSS were the major cause of device failure in the case of these inverted devices, which are compatible with full roll-to-roll (R2R) coating and industrial manufacture. The PEDOT:PSS was found to phase separate, with the PEDOT-rich phase being responsible for most of the interface degradation in oxygen atmospheres. In water atmospheres, little chemically induced degradation was observed, whereas a large partially reversible dependence of the open circuit voltage on the relative humidity was observed. In addition, temporal aspects are discussed in regard to degradation mechanisms. Finally, analytical aspects in regard to storing devices are discussed. 相似文献
