Synthesis and Thermal, Photophysical, Electrochemical Properties of 3,3-di[3-Arylcarbazol-9-ylmethyl]oxetane Derivatives

Abstract

Novel oxetane-functionalized derivatives were synthesized to find the impact of carbazole substituents, such as 1-naphtyl, 9-ethylcarbazole and 4-(diphenylamino)phenyl, on their thermal, photophysical and electrochemical properties. Additionally, to obtain the optimized ground-state geometry and distribution of the frontier molecular orbital energy levels, density functional theory (DFT) calculations were used. Thermal investigations showed that the obtained compounds are highly thermally stable up to 360 °C, as molecular glasses with glass transition temperatures in the range of 142–165 °C. UV–Vis and photoluminescence studies were performed in solvents of differing in polarity, in the solid state as a thin film on glass substrate, and in powders, and were supported by DFT calculations. They emitted radiation both in solution and in film with photoluminescence quantum yield from 4% to 87%. Cyclic voltammetry measurements revealed that the materials undergo an oxidation process. Next, the synthesized molecules were tested as hole transporting materials (HTM) in perovskite solar cells with the structure FTO/b-TiO2/m-TiO2/perovskite/HTM/Au, and photovoltaic parameters were compared with the reference device without the oxetane derivatives.

Synthesis and Characterization of New Conjugated Azomethines End-Capped with Amino-thiophene-3,4-dicarboxylic Acid Diethyl Ester

“…The two-step method was applied for the perovskite layer (MAPbI 3 ) preparation, which is described in Supplementary Information . To improve the efficiency of the cells, azomethines were doped with a different volume of lithium bis-(trifluoromethanesulfonyl)imide (Li-TFSI) with 4-tert-butyl pyridine (tBP) V tBP = 28.8 μL, the common p -dopant (to “extract” the electrons from the HTM donor molecule; V Li-TFSI = 8.75, 17.50 and 35.00 μL) [ 55 , 56 ].…”

Opto-Electronics Review

“…PSCs with the imino-triphenylamine compound acting as a holetransporting material have showed the power conversion efficiency at 14.37% [21] and 6.68% [22]. The compounds, such as oxenates [23], thiophene-based molecules [24] or 9,9-bifluorenylidene derivative [25], were also used for PSCs as hole transporting materials with a similar device design as presented in this work. All investigated solar cells have showed approximately the same or higher efficiency (PCE), reaching a value even of 7.33% [25].…”