Impact of fullerene derivative isomeric purity on the performance of inverted planar perovskite solar cells

Abstract

The effect of utilizing a pure cis-α-dimethoxy carbonyl fulleropyrrolidine C70 (DMEC70) isomer as the electron transporting material (ETM) in inverted perovskite solar cells (PSCs) was evaluated. The as-prepared C70 mono-adduct products are mixtures of regioisomers and the interest was to evaluate them independently as ETMs. Three different cis-DMEC70 isomers (α, β-endo and β-exo) (mix-DMEC70) were synthesized and purified by HPLC. It was found that PSCs based on the pure α-DMEC70 exhibit a substantially enhanced maximum power conversion efficiency (PCE) of 18.6% as compared to devices based on the mixed-DMEC70 isomers that yielded a PCE of 16.4%. A maximum PCE of 15.7% was observed for devices based on [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). This work points out the importance of using pure fullerene derivative isomers as ETMs to reduce the intrinsic energy disorder, which enhances the overall device performance.

Site‐selective Synthesis of β‐[70]PCBM‐like Fullerenes: Efficient Application in Perovskite Solar Cells

“…[10d] The use of pure isomers for improvingt he performance of the device has been demonstrated in ar ecent work in which PSCs based on pure isomers of [70]fullerene monoadducts, separated all of them by HPLC, achieved greater efficiencies than the devices based on the mixture of isomers. [13] Furthermore, as lightly beneficial performance has been found for a-pure [70]PCBM site-isomer devices when compared with commercially available a + b isomeric mixture in organic photovoltaic devices. [6a, 12d] Despite the interest in isomerically pure samples of [70]fullerene derivatives, these are obtained by tedious and time-consuming HPLC techniques.…”

Cove‐Edge Nanoribbon Materials for Efficient Inverted Halide Perovskite Solar Cells

“…These layers are invaluable because they determine the polarity of the device,i mprove stability,p assivate surface charge traps,a nd aid in chargeextraction transport from the active layer to the electrodes ( Figure 1). [11] However,the ETM is limited mainly to fullerenes such as PC 61 BM and other derivatives, [12][13][14][15][16][17] and there are few examples of efficient non-fullerene inverted PSCs reported. Despite the lower PCE at present, the inverted planar devices, which are based on p-i-n configurations,a re attractive because the relatively simple device architecture is promising for flexible devices and is amenable to low-temperature and scalable fabrication techniques.…”

“…[9,10] There are many hole transporting materials (HTMs) suitable for this type of solar cells.F or example,p oly(3,4-ethylenedioxythiophene):poly-(styrenesulfonate) (PEDOT:PSS), NiO x ,CuI, and CuSCN are all commonly used. [11] However,the ETM is limited mainly to fullerenes such as PC 61 BM and other derivatives, [12][13][14][15][16][17] and there are few examples of efficient non-fullerene inverted PSCs reported. [18][19][20][21] To further enhance PSCs,n ew ETMs must be developed and studied.…”

Cove‐Edge Nanoribbon Materials for Efficient Inverted Halide Perovskite Solar Cells

“…For example, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), NiO x , CuI, and CuSCN are all commonly used . However, the ETM is limited mainly to fullerenes such as PC 61 BM and other derivatives, and there are few examples of efficient non‐fullerene inverted PSCs reported . To further enhance PSCs, new ETMs must be developed and studied.…”