A laser-assisted chlorination process for reversible writing of doping patterns in graphene

Chemical doping can be used to control the charge-carrier polarity and concentration in two-dimensional van der Waals materials. However, conventional methods based on substitutional or surface functionalization result degradation of electrical mobility due structural disorder, maximum density is set by solubility limit dopants. Here we show that a reversible laser-assisted chlorination process create high concentrations (above 3 × 1013 cm−2) graphene monolayers with minimal drops mobility. The approach uses two lasers—with distinct photon energies geometric configurations—that are designed for subsequent chlorine removal, allowing highly doped patterns written erased without damaging graphene. To illustrate capabilities our approach, use it rewritable photoactive junctions graphene-based photodetectors.