Ionic liquid doped organic hole transporting material for efficient and stable perovskite solar cells

• As a hole transporting material (HTM), N2,N2,N2',N2',N7,N7,N7',N7'-octakis (4-methoxyphenyl) spiro [fluorene-9,9'-xanthene]-2,2',7,7'-tetraamine (X60) in mesoscopic perovskite solar cells (PSCs) has been widely utilized for substitution of the 2,2',7,7'-tetrakis (N,N-di-p-methoxyphenylamine)-9,9'-spiro-bi-fluorene (spiroOMeTAD). In this study, we have introduced an ionic liquid N-butyl-N'-(4-pyridylheptyl) imidazolium bis (trifluoromethane) sulfonamide (BuPyIm-TFSI) as a p-dopant to increase the hole conductivity and stability of the X60 based perovskite solar cells. As a result, based on the different concentrations of BuPyIm-TFSI in mesoscopic PSCs, the optimal condition (4.85 mM) showed the best power conversion efficiency (PCE) of 14.65%, which is extremely higher than the device without BuPyIm-TFSI. Moreover, the device based on X60: BuPyIm-TFSI composite HTM at ambient conditions with humidity of similar to 40% exhibited good PSCs performance with the long-term stability of 840 h. Hence, the use of BuPyIm-TFSI as a p-dopant for X60 played a significant role in enhancing the electrical properties, stability and efficiency of PSCs.

Subject headings

NATURVETENSKAP  -- Kemi -- Fysikalisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Physical Chemistry (hsv//eng)

Keyword

X60

BuPyIm-TFSI

Hole-transporting materials

Perovskite solar cells

p-Dopant

Publication and Content Type

ref (subject category)

art (subject category)