Abstract
High-quality single-wall carbon nanotube (SWCNT) films were lightly fluorinated by treatment with xenon difluoride at room temperature, which led to the formation of ionic C–F bonds on tube walls and controllable p-type doping of the nanotubes. The fluorinated SWCNT films showed improved electronic conductivity and a higher work function. In addition, the fluorination process increased the areal density of SWCNT films and decreased their surface roughness, leading to better interface contact between them and silicon. As a result, a heterojunction solar cell constructed using the lightly fluorinated SWCNT film has a high power conversion efficiency of 13.6% and excellent stability.
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•Lightly fluorinated SWCNT (F-SWCNT) film was prepared by simply exposing the free-standing SWCNT film to XeF2 gas at room temperature.•Stable C–F ionic bonds in F-SWCNT film enhanced film conductivity and caused p-type doping effect.•Fluorination improved the areal density of the SWCNT film and decreased its surface roughness.•Owing to excellent photovoltaic properties, the PCE of the F-SWCNT/Si solar cell with an active area of 9 mm2 reached 13.6%.