Triazatruxene-Based Hole Transporting Materials for Highly Efficient Perovskite Solar Cells

Abstract

Four center symmetrical star-shaped hole transporting materials (HTMs) comprising planar triazatruxene core and electron-rich methoxy-engineered side arms have been synthesized and successfully employed in (FAPbI3)0.85(MAPbBr3)0.15 perovskite solar cells. These HTMs are obtained from relatively cheap starting materials by adopting facile preparation procedure, without using expensive and complicated purification techniques. Developed compounds have suitable highest occupied molecular orbitals (HOMO) with respect to the valence band level of the perovskite, and time-resolved photoluminescence indicates that hole injection from the valence band of perovskite into the HOMO of triazatruxene-based HTMs is relatively more efficient as compared to that of well-studied spiro-OMeTAD. Remarkable power conversion efficiency over 18% was achieved using 5,10,15-trihexyl-3,8,13-tris(4-methoxyphenyl)-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole (KR131) with compositive perovskite absorber. This result demonstrates triazatruxene-based compounds as a new class of HTM for the fabrication of highly efficient perovskite solar cells.

Efficiency and stability enhancement of perovskite solar cells by introducing CsPbI3 quantum dots as an interface engineering layer

“…Here, CsPbI 3 can play a role as a hole acceptor and enhances the charge injection from the perovskite to the HTM layer due to its suitable VBP (slightly higher than that of the perovskite film). To further confirm our speculation, we performed TRPL measurements to study the hole-extraction kinetics at the perovskite−HTM interface 31 . As shown in Fig.…”

Carbon Nanotubes in TiO2 Nanofiber Photoelectrodes for High‐Performance Perovskite Solar Cells

“…The perovskite layer was deposited onto the photoelectrode films by spin‐coating as described in the literature 68. The spin‐coating recipe includes two steps, first 1000 rpm for 10 s with a ramp of 250 rpm s −1 , then 5000 rpm for 30 s with a ramp of 2000 rpm s −1 .…”

High‐Efficiency Perovskite Solar Cells Using Molecularly Engineered, Thiophene‐Rich, Hole‐Transporting Materials: Influence of Alkyl Chain Length on Power Conversion Efficiency

“…[18][19][20][21][22][23][24][25][26] An alternative chemical approach for designing high efficient HTMs is based on polycyclic aromatics as a central core, such as pentacene, [27] triazatruxene, [28] thiolated nanographene [29] or benzotrithiophene, [30] endowed with arylamines derivatives. These -conjugated structures show excellent holetransporting properties due to the stacking of the planar structure through intramolecular - interactions, which lead to excellent power conversion efficiencies.…”