Enhancement of Hole Extraction Efficiency of Dibenzothiophenes by Substitution Engineering: Toward Additive-Free Perovskite Solar Cells with Power Conversion Efficiency Exceeding 20%Show others and affiliations
2022 (English)In: Solar RRL, E-ISSN 2367-198X, Vol. 6, no 7, article id 2200128Article in journal (Refereed) Published
Abstract [en]
Replacement of hole-transporting materials (HTM) for additive-free perovskite solar cells (PSCs) is an urgent issue. In this work, three new derivatives of dibenzothiophene with methoxyphenyl, trimethoxyphenyl, carbazole moieties are synthesized as hole-transporting materials for PSCs. The hole density dynamics and hole transporting properties of synthesized dibenzothiophene derivatives are investigated by combination of the charge extraction by linearly increasing voltage (CELIV) and time-of-flight (TOF) techniques. The TOF hole mobility (mu(h)) of one compound reaches the highest value of 4.2 x 10(-3) cm(2) V(-1)s(-1) at an electric field of 2.5 x 10(5) V cm(-1), however additive-free layers in PSCs did not show the best performance. Instead, the PSC efficiency is determined by a trade-off between the hole-mobility properties and the "effective" hole recombination rate k(B) ranging 0.5-40.3 ms(-1) as determined by means of the CELIV method. The best hole extraction properties are observed for a compound with mu(h) of 9.45 x 10(-4) cm(2) V(-1)s(-1) and k(B) of 11.8 ms(-1) which is coherent with its lowest energetic disorder sigma of 78.2 meV. Having both appropriate hole density dynamics and hole-transporting properties, hole-transporting layer of that compound allows to reach PCE of 20.9% for additive-free PSC, which is among the state-of-art values for devices with undoped HTM.
Place, publisher, year, edition, pages
John Wiley & Sons, 2022. Vol. 6, no 7, article id 2200128
Keywords [en]
additive-free hole-transporting materials, energetic disorder parameters, hole mobility, hole recombination dynamics, perovskite solar cells
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-484600DOI: 10.1002/solr.202200128ISI: 000800577800001OAI: oai:DiVA.org:uu-484600DiVA, id: diva2:1700345
Funder
Swedish Foundation for Strategic Research, RMA15-01302022-09-302022-09-302023-10-31Bibliographically approved