Memory cells, and methods of forming such memory cells, are provided that include a carbon-based reversible resistivity switching material. In particular embodiments, methods in accordance with this invention form a memory cell by (a) depositing a layer of the carbon material above a substrate; (b) doping the deposited carbon layer with a dopant; (c) depositing a layer of the carbon material over the doped carbon layer; and (d) iteratively repeating steps (b) and (c) to form a stack of doped carbon layers having a desired thickness. Other aspects are also provided.