| Title |
Stability and hole-conductivity advantages of a spiro[1,3-dithiolane-2,9′-fluorene] core relative to a dibenzothiophene in hole-transporting materials with outdoor and indoor photovoltaic applications |
| Authors |
Mirakyan, Nagharsh ; Ahmed, Adnan ; Dabulienė, Asta ; Pineda, Edwin ; Durgaryan, Ranush ; Volyniuk, Dmytro ; Bezvikonnyi, Oleksandr ; Cooke, Graeme ; Jagadamma, Lethy Krishnan ; Grazulevicius, Juozas Vidas |
| DOI |
10.1021/acsaem.6c01031 |
| Full Text |
|
| Is Part of |
ACS Applied energy materials.. Washington, DC : American Chemical Society. 2026, Early access, p. 1-14.. ISSN 2574-0962 |
| Keywords [eng] |
microwave irradiation-assisted Buchwald-Hartwig cross-coupling reaction ; dibenzothiophene ; spiro[1,3-dithiolane-2-9 '-fluorene] ; indoor and outdoor perovskite solar cells |
| Abstract [eng] |
Two hole-transporting compounds with the same side-donor moiety and different central fragments, i.e., those of dibenzothiophene or spiro[1,3-dithiolane-2,9′-fluorene] are reported. They are synthesized using microwave irradiation-assisted Buchwald–Hartwig cross-coupling reactions, which are completed within 15–40 min. The solid films of the compounds are characterized by low ionization energies of ca. 5.0 eV. According to charge extraction by linearly increasing voltage (CELIV) and time-of-flight experiments, the spiro[1,3-dithiolane-2,9′-fluorene] derivative exhibits higher hole mobility (1.8 × 10–4 cm2/V·s at an electric field of 3.17 × 105 V/cm) than the dibenzothiophene-based counterpart (4.6 × 10–5 cm2/V·s at the same electric field). Both the compounds are characterized by high electrochemical stability, as evidenced by reversible cyclic voltammograms. The compounds exhibit high glass transition temperatures of 142 and 163 °C, suggesting high morphological stability of their solid amorphous films. The spiro[1,3-dithiolane-2,9′-fluorene] derivative exhibits significantly higher photochemical stability in comparison to that of the dibenzothiophene-based compound, as evidenced by the constant intensity of fluorescence of the toluene solutions and films under UV irradiation. Its films exhibit high conductivity, confirmed by CELIV in the dark. Perovskite solar cells demonstrate the highest stability and efficiency when the spiro[1,3-dithiolane-2,9′-fluorene] derivative is used for the deposition of hole-transporting layers. Under solar and indoor illumination, maximum power conversion efficiencies of 15.5 and 30%, respectively, are achieved, demonstrating the potential of spiro[1,3-dithiolane-2,9′-fluorene] derivatives over dibenzothiophene derivatives in molecular structure designs. |
| Published |
Washington, DC : American Chemical Society |
| Type |
Journal article |
| Language |
English |
| Publication date |
2026 |
| CC license |
|
