title: 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.
authors.forename: Kasparas
authors.initials: K
authors.lastname: Rakstys
authors.forename: Antonio
authors.initials: A
authors.lastname: Abate
authors.forename: M Ibrahim
authors.initials: MI
authors.lastname: Dar
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.affiliation: Department of Solid State Electronics, Vilnius University , Sauletekio 9, Vilnius 10222, Lithuania.
authors.forename: Vygintas
authors.initials: V
authors.lastname: Jankauskas
authors.forename: Gwénolé
authors.initials: G
authors.lastname: Jacopin
authors.affiliation: Department of Solid State Electronics, Vilnius University , Sauletekio 9, Vilnius 10222, Lithuania.
authors.forename: Egidijus
authors.initials: E
authors.lastname: Kamarauskas
authors.affiliation: Abengoa Research , Abengoa, C/Energía Solar no 1, Campus Palmas Altas, Sevilla 41014, Spain.
authors.forename: Samrana
authors.initials: S
authors.lastname: Kazim
authors.affiliation: Abengoa Research , Abengoa, C/Energía Solar no 1, Campus Palmas Altas, Sevilla 41014, Spain.
authors.forename: Shahzada
authors.initials: S
authors.lastname: Ahmad
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
authors.forename: Mohammad Khaja
authors.initials: MK
authors.lastname: Nazeeruddin