Performance Evaluation of an Organic Thin-Film Solar Cell of PTB7:PC₇₁BM with an Alcohol-Soluble Polyelectrolyte Interlayer Prepared Using the Spray-Coating Method

Abstract

We report the effect of a poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl fluorene)] (PFN) interlayer on the performance of PTB7:PC 71 BM-based organic thin-film solar cells (OTFSCs) prepared using the spray-coating method. The active layer shows a broad absorption, but the effective contact area in the bulk hetrojunction (BHJ) is small because of the formation of aggregates on the surface. The surface aggregates dissolved by the addition of 1,8-diiodooctane (DIO) to the PTB7:PC 71 BM matrix, which results in an increase in the contact area between the donor and acceptor in the active layer and, thereby , an improvement in the device performance. The PFN interlayer enhances the charge-transport properties and suppresses exciton-recombination processes. This results in increases in the short-circuit current density (J sc = 13.87 mA/cm 2 ), open-circuit voltage (V oc = 0.747 V), and fill factor (FF = 57.97%), as a result of a high power conversion efficiency (PCE, η = 6.01%) compared to a device without a PFN layer (η = 4.84%). The thickness of the PFN interlayer was found to be of siginificant importance, as thicker layers exhibit an insulating nature instead of improving the electron transfer.

Effect of aggregation behavior and phenolic hydroxyl group content on the performance of lignosulfonate doped PEDOT as a hole extraction layer in polymer solar cells

“…PEDOT only showed a bad PCE of 2.91% with a FF of 48.04%. The same devices (ITO/HEL/PTB7:PC71BM/Al) with PEDOT:PSS modified anode showed a J SC of 12.77, V OC of 0.72 and PCE of 4.28% with a FF of 46.40% as shown in reference 46 . The PCE of It encourages us to study its potential further in future.…”

Bimolecular Excited-State Electron Transfer with Surprisingly Long-Lived Radical Ions

“…Such information is critically important in developing solar cell materials based on water or organic solvent-soluble polyfluorenes 21 and on solid-phase polyfluorenes. 33 Here, we report PET dynamics in non-covalent associations of cationic polyfluorene, namely poly[(9,9-di(3,3'-N,N'-trimethyl-ammonium) propyl fluorenyl-2,7-diyl)-alt-co-(9,9-dioctylfluorenyl-2,7-diyl)] diiodide salt (PFN) with neutral electron acceptor 1,4-dicyanobenzene (DCB). We carefully chose DCB as an electron acceptor because of its unique optical properties including the absence of a spectral overlap with the donor to rule out the possibility of energy transfer process rat.…”

High performance airbrush spray coated organic solar cells via tuning the surface tension and saturated vapor pressure of different ternary solvent systems

“…When the o-DCB volume content ratio exceeds 60 vol.%, J SC and PCE are both decreased to 13.7 mA/cm 2 16.1 mA/cm 2 and 63.1%, respectively, resulting in the PCE of 7.62% accordingly. The performance of our AS coated device in air ambient is as high as the OSCs based on PTB7:PC 71 BM using conventional spin coated method in nitrogen ambient [41], and to the best our known, it is the highest performance using AS coating method [29]. Then, when the ratio of o-Xy is more than 20 vol.%, the device performance of OSC will gradually decrease.…”

“…Numerous physical properties of the solution, such as the surface tension (ST), volatility and wettability, directly affect the AS processes of atomization, flying and deposition [27,28]. For instance, the photovoltaic performances of OSCs based on PTB7:PC 71 BM BHJ system with high PCEs up to 7-9% from spin coating method decrease to the PCE of 5-6% when using AS coating method [29,30]. It is found that the conventional BHJ system only with a single solvent and additive cannot perfectly match with the AS coating method due to the simplex physical property of solution, which usually results in large aggregation domains as well.…”