Thienylvinylenethienyl and Naphthalene Core Substituted with Triphenylamines—Highly Efficient Hole Transporting Materials and Their Comparative Study for Inverted Perovskite Solar Cells

Abstract

In this report, two simple cost efficient solution processable small molecular hole transporting materials (HTMs) are synthesized and used successfully in inverted perovskite devices. These HTMs, namely (E)‐4,4'‐(ethene‐1,2‐diylbis(thiophene‐5,2‐diyl))bis(N,N‐bis(4‐methoxyphenyl)aniline) (TPA‐TVT‐TPA) and 4,4'‐(naphthalene‐2,6‐diyl)bis(N,N‐bis(4‐methoxyphenyl)aniline) (TPA‐NAP‐TPA), are designed by using triphenylamine methoxy as common end capping groups with thienylvinylenethienyl and naphthalene cores respectively. They possess good solubility in common organic solvents. Additionally, they have not only appropriate highest occupied molecular orbital energy levels for good hole injection ability but also sufficient lowest unoccupied molecular orbital for electron blocking capability. The power conversion efficiency (PCE) of these HTMs based devices is found to be of 16.32% for TPA‐TVT‐TPA and 14.63% for TPA‐NAP‐TPA. Particularly, TPA‐TVT‐TPA exhibits an impressive Voc of 1.07 V. The obtained performance is one of the highest performances in inverted perovskite layouts. The cut‐price and straightforward synthesis with elegant scale up makes these classes of materials important for the industry to produce high‐throughput printed perovskite solar cells for large area applications.

Efficient and Stable Inverted Planar Perovskite Solar Cells Using a Triphenylamine Hole‐Transporting Material

“…[33] For example, using dopant-free Trux-OMeTAD, aP CE of 18.6 %w as achieved. [31] The above work indicates that small molecules are promisingH TMs for inverted PSCs.Herein, we introduce an organic small molecule m-MTDATA to replace PEDOT:PSS in inverted PSCs without dopantsu sing the following device architecture:g lass/fluorine-doped tin oxide (FTO)/HTM/perovskite/C 60 /2,9-dimethyl-4,7-diphenyl-1,10phenanthroline (BCP)/Cu. [31] The above work indicates that small molecules are promisingH TMs for inverted PSCs.…”

“…[33] For example, using dopant-free Trux-OMeTAD, aP CE of 18.6 %w as achieved. [31] The above work indicates that small molecules are promisingH TMs for inverted PSCs. [31] The above work indicates that small molecules are promisingH TMs for inverted PSCs.…”

Application of Hole-Transporting Materials as the Interlayer in Graphene Oxide/Single-Wall Carbon Nanotube Silicon Heterojunction Solar Cells

“…[28,29] Synthesis of 4,4 0 -(Naphthalene-2,6-diyl)bis(N,N-bis (4-methoxyphenyl)aniline) (TPA-NAP-TPA) In a round-bottom flask 2,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)naphthalene (150 mg, 0.395 mmol), 4-bromo-N, N-bis (4-methoxyphenyl)aniline (455 mg, 1.184 mmol), and 2 M aqueous K 2 CO 3 solution (12 mL) were dissolved in degassed toluene (18 mL). The solution was purged with argon for 15 min, then tetrakis(triphenylphosphine)palladium (16.18 mg 0.014 mmol) was added.…”

“…[23] Recently, 2,2 0 ,7,7 0 -tetrakis(N,N 0 -di-p-methoxyphenylamine)-9,9 0 -spirobiuorene (spiro-OMeTAD), which plays the same role in a GOCNT/Si solar cell, has successfully improved efficiency to above 13 % [24] owing to improved hole transport. [25][26][27] In addition to these traditional materials, there are also some recently synthesised new low-cost hole-transporting layer (HTL) materials, which have been successfully applied in perovskite solar cells, such as 4,4 0 -(naphthalene-2,6-diyl)bis(N, N-bis (4-methoxyphenyl)aniline) (NAP) [28] and (E)-4 0 ,4 000 -(ethene-1,2-diyl)bis(N,N-bis(4-methoxyphenyl)-[1 00 ,1 000 -biphenyl]-4-amine) (BPV) with comparable efficiency to that of spiroOMeTAD. [29] Based on these ideas, these new materials, as well as PEDOT:PSS, which have been widely used in many other devices, including dye-sensitised solar cells, [30][31][32][33] perovskite solar cells, [34][35][36] and organic photovoltaics, [37][38][39] may be able to improve the performance of GOCNT/Si solar cells by serving as an HTL and thus enhance diode properties with limited light absorption at the same time, as shown in Fig.…”

“…The UV-vis-near infrared (NIR) spectra show that the as-prepared film has a broad absorbance feature above 1500 nm with a reasonably sharp peak at ,1100 nm (Fig. 2a), which were assigned to absorbance from the first and second van Hove singularities of [28,29] schematic structures of (c) GOCNT/Si, and (d) GOCNT/HTL/Si devices (GOCNT/PEDOT:PSS/Si, GOCNT/ NAP/Si, and GOCNT/ BPV/Si). The band gap of GOCNT is estimated from the peak position of S 11 in UV-vis-NIR absorbance of the GOCNT hybrid electrode.…”