Possible n/p-type conductivity of two-dimensional graphene oxide by boron and nitrogen doping: Evaluated via constrained excitation

As thefirst-principles calculations using the supercell approximation give widely scattered results in a two-dimensional charged system, making the evaluation of defectionization energy difficult, here an alternative constrained excitation is applied to overcome this problem for defect analysis. As an example ingraphene oxide with 50% oxygen coverage (according to the popular epoxy-chain-plus-hydroxyl-chain model), the structures, stabilities, and electronic properties of nitrogen andborondopants are investigated. Generally,boron prefers to replacecarbon in thesp3 region as an acceptor while nitrogen has a tendency to substitute thesp2carbon close to the boundary between thesp2 region and thesp3 region as a donor. Theirionization energies are 0.24 –0.42 eV forboron and 0.32 –0.67 eV for nitrogen. However, a special case of nitrogendoped in the boundary-sp3carbon can change to be an acceptor with the assistance of its neighboring (epoxy) oxygen “Lift-off,” leading to the shallowestionization energy of 0.12  eV and the best candidate forp-typeconductivity. The present study offers the detailed pictures ofboron and nitrogen defects ingraphene oxide for the potentialn- andp-typeconductivity.

Source: Applied Physics Letters - November 16, 2016 Category: Physics Authors: Dan Wang, Dong Han, Xian-Bin Li, Sheng-Yi Xie, Nian-Ke Chen, Wei Quan Tian, Shengbai Zhang and Hong-Bo Sun Source Type: research