Poly(3-dodecylthiophene)-grafted multi-walled carbon nanotubes: an additive for improving charge transport properties of triple cation perovskite solar cells

In this study, different percentages of multi-walled carbon nanotubes grafted with poly(3-dodecylthiophene) (MWCNT-g-PDDT) and pure MWCNT were used in Cs(0.05)FA(0.79)MA(0.16)PbI(2.5)Br(0.5) triple cation perovskite active layer to survey the morphological, optical, and photovoltaic properties of the corresponding solar cell devices. Field emission scanning electron microscopy manifested smooth, dense, and pin-hole free surface by introducing MWCNT-g-PDDT into the perovskite active layer. MWCNT-g-PDDT additive boosted the photo-response of the perovskite layer in the visible wavelength range of 500-730 nm. Photoluminescence (PL) spectroscopy revealed a significant quenching effect; as a result of an effective charge extraction. High absorption coefficient and suppressed non-radiative recombination are responses for increased current density 19.40 mA cm(-2). Furthermore, photovoltaic parameters of devices modified with MWCNT-g-PDDT additive exhibited improvement, due to a reduction in charge transfer resistance (R-ct) and compact surface.

Automated summary

In this study, the effects of adding MWCNT-g-PDDT and pure MWCNT in the perovskite active layer were investigated. The addition of MWCNT-g-PDDT led to a smooth and dense surface, increased photo-response, and improved photovoltaic performance. The modified devices showed reduced charge transfer resistance and compact surface, resulting in improved photovoltaic parameters.