Modified HTL-induced efficiency enhancement for inverted perovskite solar cells.

Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was doped by 3-(Cyclohexylamino)-2-hydroxy-1-propanesulfonic acid (CAPSO), leading to dramatic improvement of its conductivity and consequently efficiency enhancement in inverted perovskite solar cells (PSCs) based on PEDOT:PSS hole transport layer (HTL). Under the optimized CAPSO doping concentration, the conductivity of PEDOT:PSS film increased by about three orders of magnitude, and this is interpreted by the weakening of the coulombic attractions between PEDOT and PSS components induced by CAPSO. CAPSO doped PEDOT:PSS (PEDOT:PSS@CAPSO) was applied as HTL of PSCs devices based on CH 3 NH 3 PbI 3 layers, leading to the best power conversion efficiency (PCE) of ~38% enhanced relative to those of the corresponding reference devices based on pristine PEDOT:PSS HTL. Scanning Kelvin probe microscopy (SKPM) results show that the work function of PEDOT@CAPSO matches well with the valence band of CH 3 NH 3 PbI 3 absorbers. The research demonstrates that the zwitterion modified PEDOT:PSS could act as an outstanding hole transport material for fabricating high-efficient perovskite solar cells. A new zwitterion, 3-(Cyclohexylamino)-2-hydroxy-1-propanesulfonic acid (CAPSO), induced to dope PEDOT:PSS, leading to a dramatic increase of the conductivity of PEDOT:PSS film. PEDOT:PSS@CAPSO was incorporated as hole transport layer (HTL) in inverted perovskite solar cells devices based on CH3NH3PbI3, resulting in obvious efficiency enhancements, which is attributed to the conjunct factors including the increase of the crystallinity of perovskite layer and the improved conductivity of PEDOT:PSS HTL. Image 1 • A new zwitterion, CAPSO, introduced to dope PEDOT:PSS, leading to a dramatic increase of the conductivity of PEDOT:PSS film. • PEDOT:PSS@CAPSO was incorporated as hole transport layer (HTL) in inverted perovskite solar cells based on CH 3 NH 3 PbI 3. • Modified PEDOT:PSS HTL induced obvious efficiency enhancement for inverted perovskite solar cells. • Improved efficiency is due to the increased crystallinity of perovskite layer and improved conductivity of PEDOT:PSS HTL. [ABSTRACT FROM AUTHOR]