Variation of Interfacial Interactions in PC61BM-like Electron-Transporting Compounds for Perovskite Solar Cells

Olivia Fernandez-Delgado; Edison Castro; Carolina R Ganivet; Kaylin Fosnacht; Fang Liu; Tom Mates; Ying Liu; Xiaojun Wu; Luis Echegoyen

doi:10.1021/acsami.9b09018

Variation of Interfacial Interactions in PC₆₁BM-like Electron-Transporting Compounds for Perovskite Solar Cells

ACS Appl Mater Interfaces. 2019 Sep 18;11(37):34408-34415. doi: 10.1021/acsami.9b09018. Epub 2019 Jul 31.

Authors

Olivia Fernandez-Delgado¹, Edison Castro^{1

2}, Carolina R Ganivet¹, Kaylin Fosnacht^{1

3}, Fang Liu⁴, Tom Mates⁵, Ying Liu⁶, Xiaojun Wu⁶, Luis Echegoyen¹

Affiliations

¹ Department of Chemistry and Biochemistry , University of Texas at El Paso , 500 West University Avenue , El Paso , Texas 79968 , United States.
² Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States.
³ Department of Natural Sciences , Saint Martin's University , Lacey Washington 98503-7500 , United States.
⁴ Department of Chemistry , Columbia University , New York , New York , 10027 , United States.
⁵ Materials Department , University of California in Santa Barbara , California 93106-5050 , United States.
⁶ Hefei National Lab for Physical Sciences at the Microscale, School of Chemistry and Material Sciences, and CAS Key Laboratory of Materials for Energy Conversion , University of Science and Technology of China , Hefei , Anhui 230026 , China.

PMID: 31318519
DOI: 10.1021/acsami.9b09018

Abstract

The synthesis, characterization, and incorporation of phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM)-like derivatives as electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs) are reported. These compounds have the same structure except for the ester substituent, which was varied from methyl to phenyl to thienyl and to pyridyl. The three latter derivatives performed better than PC₆₁BM in PSCs, mainly attributed to the specific interactions of the fullerenes with the perovskite layer, as evidenced by X-ray photoelectron spectroscopy (XPS) and steady-state and time-resolved photoluminescence (SS- and TRPL) measurements. The experimental results were fully supported by density functional theory (DFT) calculations, which showed that the strongest interactions were exhibited by the compound possessing the pyridyl substituent.

Keywords: electron transporting materials; fullerene derivatives; interfacial interactions; perovskite solar cells; pyridine; thiophene.