Spontaneous generation of interlayers in OPVs with silver cathodes: enhancing V_oc and lifetime

Abstract

A major contribution to the performance improvement of organic photovoltaic (OPV) devices is due to the successful engineering of the metal/organic interface by generating interlayers.

A Self‐Organized Poly(vinylpyrrolidone)‐Based Cathode Interlayer in Inverted Fullerene‐Free Organic Solar Cells

“…The self‐organization method not only simplifies the fabrication procedure significantly but also makes the tolerance of the interlayer to thickness variation no need consideration. And hence, intensive investigations have been focused on the self‐organization method in fullerene‐based OSCs …”

“…The self‐organization method is based on the self‐assembly of the interlayer material during the film deposition process, and many factors have been suggested to explain the origin of the migration of the interlayer materials. It has been demonstrated that when an interlayer material has higher surface energy and stronger interaction with the indium tin oxide (ITO) electrode, it may tend to migrate to the near ITO side, and vice versa . For instance, Wei et al introduced fluorocarbon chains to [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC 61 BM) to decrease the surface energy of PC 61 BM, and as a result, the fluorinated PC 61 BM segregated to the top of the AL, forming the CIL and AL simultaneously .…”

“…By contrast, when PC 61 BM was substituted with high‐surface‐energy moieties, such as amino groups, the modified PC 61 BM could migrate to the interface between the AL and the ITO substrate . Interestingly, poly(ethylene glycol) (PEG) and its derivatives, materials with high surface energies, have been demonstrated to prefer to self‐organize at the top of the AL because of the strong interaction between the PEG segment and the top metal electrode . Poly(vinylpyrrolidone) (PVP), poly(2‐vinylpyridine) (P2VP), poly[(9,9‐bis(30‐(N,N‐dimethylamino)propyl)‐2,7‐fluorene)‐ alt ‐2,7‐(9,9‐dioctylfluorene)] (PFN), polyethyleneimine (PEI), oleamide, and fluorinated zinc oxide have also been used to self‐organize CILs in OSCs .…”

Improvement of PEDOT:PSS linearity via controlled addition process

“…9 Among these, PEDOT:PSS exhibits the best electrical and optical properties [10][11][12][13][14] and is utilized in organic electronic devices such as organic light emitting diodes (OLEDs) 15 and organic photovoltaics (OPVs). 16 Therefore, it is considered as a potential organic electronic material.…”

The interfacial degradation mechanism of polymer:fullerene bis-adduct solar cells and their stability improvement

“…S6 (ESI †) shows the XPS spectra of C 1s and S 2p of P3HT:bis-PC 61 BM blend films with different concentrations of piperazine. As seen here, the C 1s peak can be fitted into two components, corresponding to C-C at 284.78 eV and C-O at 285.91 eV, 39 where the C-O signal can be assigned to the component of bis-PC 61 BM. Fig.…”