Release Time:2019-03-13  Hits:

Indexed by: Journal Article

Date of Publication: 2016-01-01

Journal: RSC ADVANCES

Included Journals: EI、SCIE

Volume: 6

Issue: 99

Page Number: 96990-96996

ISSN: 2046-2069

Abstract: 2,2',7,7'-Tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) currently is the most common hole transport material (HTM) used in perovskite solar cells (PSCs). Whereas, the hole mobility of amorphous spiro-OMeTAD remains low and may result in severe charge recombination. In addition, the harsh conditions and high cost of spiro-OMeTAD synthesis are also disadvantageous for future large-scale applications. In this paper, we report the synthesis of a new, high-yielding spiro-type HTM, 2,7-di(N,N-di-p-methoxyphenylamine)-2',7'-di-tert-butyl-9,9'-spirobifluorene (spiro-027). The replacement of two 4,4'-dimeoxyl-diphenylamine at the 2' and 7' positions of conventional spiro-OMeTAD with two tert-butyl in spiro-027 results in a greatly simplified molecular structure with unaffected thermal stability or highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). In addition, enhanced hole mobility is observed in spiro-027. Thus, the PSC devices based on spiro-027 demonstrated a high power conversion efficiency (PCE) of 16.60%, which was higher than the 16.12% PCE achieved by those based on spiro-OMeTAD. By combining these results with theoretical calculations, our work confirmed the feasibility of simplifying the molecular structure of spiro-OMeTAD, which contributed to our knowledge of spiro-type optoelectronic functional materials. Moreover, our results offer a novel strategy for the replacement of expensive HTMs and the enhancement of PSCs performance.