Flexible, High Temperature, Planar Lighting with Large Scale Printable Nanocarbon Paper

A nanocarbon paper was demonstrated composed of monolayer graphene-oxide (GO) nanosheets interpenetrated with 10 wt% single walled carbon nanotubes (CNTs). A unique two-step reduction process is used to convert the paper to a highly graphitic, highly conducting form, which leads to compelling lighting performance. The first thermal reduction step leads to moderately reduced-grapheneoxide (RGO) paper mixed with CNTs, while the second, higher temperature step further purifies the RGO-CNT paper and leads to improved crystallinity of the graphene planes. After the two-step reduction, the RGO-CNT paper shows excellent graphene-like Raman spectra with a dense structure and a record high electrical conductivity at room temperature. This high purity RGO-CNT paper can routinely sustain T = 3000 K, with one sample reaching 3320 ± 50 K, significantly higher than observed for papers made from CNTs or graphene sheets only. This ultrathin, freestanding RGO-CNT paper leads to lighting efficiency in vacuum comparable to or potentially higher than that of tungsten wires in argon gas.