Achieving over 21% efficiency in inverted perovskite solar cells by fluorinating a dopant-free hole transporting material

Abstract

PFDT-COOH and PFDT-2F-COOH were developed as dopant-free hole transporting materials for inverted PSCs. The PFDT-2F-COOH device obtained a high PCE of 21.68% due to the fluorination effect.

The impact of fluorine atoms on a triphenylamine-based dopant-free hole-selective layer for perovskite solar cells

“…The component at 283.7, 285.2, and 287.2 eV in C1s spectrum are related to C-C of impurities, 42 C-NH2 in MA and C=NH2 + in FA respectively (Figure 3A). 43,44 in the intensity of C-NH2 and C=NH2 + peaks are in line with the ratio of FA and MA in FAMA. In the FAMA sample coated with FOMePh, the intensity of C-C and C-N has been decreased and shifted 0.9 and 0.7 eV toward higher binding energy respectively (Figure 3B).…”

Interface Optimization via Fullerene Blends Enables Open‐Circuit Voltages of 1.35 V in CH3NH3Pb(I0.8Br0.2)3 Solar Cells

“…[ 12 ] In inverted (anode‐illuminated) perovskite solar cells, fullerenes are nearly always used as electron transport layers and high efficiency solar cells with fullerene electron transport layers based on C 60 [ 30,31 ] and [6,6]‐phenyl‐C 61 ‐butyric acid methyl ester (PCBM) have been demonstrated for a range of bandgaps. [ 4,32–38 ] However, fullerenes have also restrictions in so far that their energy levels cannot easily be tuned over a wide range. The electron affinity of fullerenes changes with the number and type of adducts attached to the C 60 cage with multiadducts leading to lower electron affinities relative to monoadducts such as PCBM or even C 60 .…”

Facile Fabrication of Self‐Assembly Functionalized Polythiophene Hole Transporting Layer for High Performance Perovskite Solar Cells

“…[ 27,34 ] Note that, the arrangement of carboxylic groups on ITO has been reported to induce an interfacial dipole and passivate the ITO surface which can facilitate the holes collection and blocking the carrier recombination. [ 35 ] It may also arise from weak P3HT aggregation and the well oriented polymer chain arrangement with a coil‐like conformation. [ 27 ]…”