Single-walled carbon nanotubes’ (SWNTs) impressive electronic properties have made these tiny structures promising materials for numerous electronics applications. Getting the most out of SWNTs requires carefully controlling their purity. Adsorbed oxygen, for example, alters nanotube conductivity and other properties. For that reason, SWNTs are typically heated in vacuum to remove the oxygen. That laborious and time-consuming process may become a thing of the past thanks to a simpler and more effective combined chemical and electrical treatment (Nano Lett. 2014, DOI: 10.1021/nl502401c). A team led by Xiaokai Li, Nilay Hazari, and André D. Taylor of Yale University reports that exposing SWNTs to hydrogen fluoride vapor and then applying a constant electrical current rids the nanotubes of oxygen and conditions them for electronics applications. In a demonstration, the team compared silicon solar cells featuring transparent electrodes made from thin films of SWNTs. Solar cells made with nanotubes that were subjected to the HF-plus-electrical treatment exhibited record-setting values of conversion efficiency—the ratio of light energy in to electrical energy out. The team reports that the combined treatment led to better performance than either treatment step alone or the standard vacuum heating method.