Release Time:2019-03-09  Hits:

Indexed by: Journal Papers

Date of Publication: 2015-11-01

Journal: JOURNAL OF ENERGY CHEMISTRY

Included Journals: Scopus、ISTIC、EI、SCIE

Volume: 24

Issue: 6,SI

Page Number: 698-706

ISSN: 2095-4956

Key Words: Dopant-free; Perovskite solar cell; Hole transport material; Phenoxazine; Thin film

Abstract: Based on the previous research work in our laboratory, we have designed and synthesized a small-molecule, hole transport material (HTM) POZ6-2 using phenoxazine (POZ) as central unit and dicyanovinyl units as electron-withdrawing terminal groups. Through the introduction of a 2-ethyl-hexyl bulky chain into the POZ core unit, POZ6-2 exhibits good solubility in organic solvents. In addition, POZ6-2 possesses appropriate energy levels in combination with a high hole mobility and conductivity in its pristine form. Therefore, it can readily be used as a dopant-free HTM in perovskite solar cells (PSCs) and a conversion efficiency of 10.3% was obtained. The conductivity of the POZ6-2 layer can be markedly enhanced via doping in combination with typical additives, such as 4-tert-butylpyridine (TBP) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). Correspondingly, the efficiency of the PSCs was further improved to 12.3% using doping strategies. Under the same conditions, reference devices based on the well-known HTM Spiro-OMeTAD show an efficiency of 12.8%. (C) 2015 Science Press and Dalian Institute of Chemical Physics. All rights reserved.