Simple carbazole-based hole transporting materials with fused benzene ring substituents for efficient perovskite solar cells

Abstract

Carbazole-based HTMs with fused benzene rings as substituents show a power conversion efficiency exceeding 17% (13.7% for Spiro-OMeTAD under the same conditions).

Low-Temperature Hydrothermal Growth of ZnO Nanowires on AZO Substrates for FACsPb(IBr)3 Perovskite Solar Cells

“…While many mechanisms have been discussed [80,81] to interpret the evolution of the perovskite active layer in these conditions, explaining common losses in V oc and FF [82], this strong difference in device behavior suggests a specific role played by the carbazole HTL in device degradation. While Cz-Pyr shows a relatively lower glass transition temperature than spiro-OMeTAD [50], these results indicate a beneficial interfacial configuration with the perovskite active layer, which positively affects the performance evolution with time. The role of the dopants (tert-butyl pyridine and lithium salt), which are known to be a major source of performance drop in the case of spiro-OMeTAD [75], remains to be clarified in this case as well.…”

“…Regarding the nature of the HTL, Cz-Pyr-based devices exhibit much lower J sc values compared to devices based on spiro-OMeTAD. Such observation can be related to a larger hole mobility for spiro-OMeTAD (2.5 × 10 −5 cm 2 V −1 s −1 ) as measured using field-effect transistors in saturation regime, compared to Cz-Pyr (7.4 × 10 −6 cm 2 V −1 s −1 ) [50]. The incident photon-to-current conversion efficiency (IPCE) measurements show that the use of 0.40 µm long NWs instead of 0.25 µm enhances the photocurrent in the whole spectral region under study (300-800 nm), with both spiro-OMeTAD and Cz-Pyr (see Figure S10).…”

“…For comparison, an alternative hole transport layer made of 3,6-Bis[N,N -di(4-methoxyphenyl)amino]-9-(1-pyrenyl)carbazole (Cz-Pyr) was prepared by dissolving 49 mg Cz-Pyr in 0.500 mL chlorobenzene, where 8.75 µL LiTFSI and 14.4 µL tBP were added. Cz-Pyr HTL was recently demonstrated as a relevant alternative to spiro-OMeTAD, leading to similar photovoltaic performance [50]. Finally, an Au electrode (~100 nm) was deposited by using thermal evaporation under secondary vacuum through a shadow mask, defining the active area of the cell (>0.22 cm 2 ).…”

“…Carbazole-based derivatives as HTL in perovskite solar cells have attracted attention because of their photochemical properties and their promising characteristics such as high mobilities, good charge transport, and high efficiencies [75][76][77][78]. In this context, reported Cz-Pyr [50] has been compared with the reference spiro-OMeTAD as HTL. In short, in this subsection, optimized NW growth conditions (i.…”

Interface compatibility: how to outperform classical spiro-OMeTAD in perovskite solar cells with carbazole derivatives

“…Also, carbazole-based molecules are currently among the most promising HTMs, [41][42][43][44][45] and the selected Cz-P and Cz-Pyr HTMs exhibit performances competing and outperforming spiro-OMeTAD. 46,47 In order to investigate the outstanding performance of the IL, planar organic-inorganic lead halide PSCs with the n-i-p architecture were built w/o a polymer IL, as well as reference devices with the standard spiro-OMeTAD as the HTM. This is, to the best of our knowledge, the first report on a dual-function IL material designed to both passivate trap states and exhibit strong compatibility with the HTM layer.…”