A combination of Al-doped ZnO and a conjugated polyelectrolyte interlayer for small molecule solution-processed solar cells with an inverted structure

Abstract

We successfully demonstrate a smart strategy to use aluminum doped ZnO (AZO) and the thiophene-based conjugated polyelectrolyte P3TMAHT as an interfacial layer in small molecule solution-processed inverted solar cells. Modification of AZO with a thin P3TMAHT layer increases the photovoltaic properties of the inverted cell as a result of reduction in the work function of the cathode with well aligned frontier orbital energy levels for efficient charge transport and reduced surface recombination. The inverted device achieved $16% performance improvement dominantly by recapturing part of the V oc losses when going from conventional to the inverted architecture. In addition, the inverted device using the AZO/P3TMAHT interlayer shows improved device stability in air compared to conventional devices.

A solution-processed barium hydroxide modified aluminum doped zinc oxide layer for highly efficient inverted organic solar cells

“…ethanolamine, methanol and ethanol) was reported to improve the contact properties. 19,30,31 The most popular interfacial dipole layers reported were self-assembled monolayers (SAMs), 32,33 conjugated polyelectrolytes (CPEs) 21,[34][35][36] or polyelectrolyte layers (PEs), 37 which all enhanced the power efficiency of OSCs by reducing the work function difference between MeO x and PCBM and further by reducing defect or trap-assisted recombination at the interface.…”

Low-energy electron transmission for the analysis of the interface barrier formation and the density of the unoccupied electronic states in the ultra-thin layers of fluorinated copper-phthalocyanine

“…Electronic properties of thin and ultra-thin conjugated organic films and of their hetero-junctions with metals and inorganic semiconductors have attracted scientific interest because of possible applications in chemical sensing, light-emitting and photovoltaic devices [1][2][3][4][5]. The surface science techniques were used successfully to characterize the interfacial band alignment and the density of the electronic states at organic film interfaces with metal and semiconductor surfaces [6,7].…”

Density of the unoccupied electronic states of the ultrathin films of the aziridinylphenylpyrrol substituted fullerene

“…Electronic properties of the surfaces of the conjugated organic materials have attracted scientific interest because of possible applications in organic electronics devices as well as in single-molecule devices [1][2][3][4][5]. The surface science techniques were used successfully to characterize the energy level alignment and the density of the electronic states at organic film interfaces with metal and semiconductor surfaces [6,7].…”