Simplifying the doping process for hole transport materials

The power conversion efficiency of perovskite solar cell technologies now rivals that of silicon-based technologies. However, barriers still remain in their progress toward commercialization. One such barrier is the slow and expensive doping process, which is required to enhance the p-type character of the hole transporting materials that are layered between the perovskite film and the anode. Here, André Taylor and colleagues report a new method, using CO₂ and UV light to dope spiro-OMeTAD:LiTFSI (a common hole transporting material), increasing the conductivity by 1–2 orders of magnitude in a matter of minutes. Solar cell devices containing this doped material show enhanced efficiencies relative to conventional doped interlayers. This process reduces fabrication time by several hours, offering the potential to facilitate large volume manufacturing of this promising technology.