Simple Salt-Coordinated n-Type Nanocarbon Materials Stable in Air

After more than three decades of molecular and carbon-based electronics, the creation of air-and thermally stable n-type materials remains a challenge in the development of future p/n junction devices such as solar cells and thermoelectric modules. Here a series of ordinary salts are reported such as sodium chloride (NaCl), sodium hydroxide (NaOH), and potassium hydroxide (KOH) with crown ethers as new doping reagents for converting single-walled carbon nanotubes to stable n-type materials. Thermoelectric analyses reveal that these new n-type single-walled carbon nanotubes display remarkable air stability even at 100 degrees C for more than 1 month. Their thermoelectric properties with a dimensionless fi gure-of-merit (ZT) of 0.1 make these new n-type single-walled carbon nanotubes a most promising candidate for future n-type carbon-based thermoelectric materials.