Graphene, having a perfect two-dimensional crystal structure, has many excellent features such as a high specific surface area, and extraordinary electrical, thermal and mechanical properties. However, its usage in electronic devices is possible only if band gap of desired value is induced in this gapless semi-metal. Therefore, first principle calculations have been carried out to investigate the role of oxygen (O) doping versus adsorption and, the impurity concentration and coverage to induce band gap in graphene employing PBE at GGA level. The band gap is induced owing to production of vacancies, dissociative adsorption of oxygen, subsituational doping and pre-dissociated oxygen adsorption. It is interesting to note that band gap is introduced by both the processes of doping and adsorption of O. The oxygen doping leads to induction of two energy gaps, smaller in value above and larger below the Fermi level; while adsorption irrespective of adsorption configuration produces single direct gap. Increase both in concentration and coverage leads to enhance band gap value maximum being 1.85 eV in case of hexagonal doping of 12.5% concentration with an exception in adsorption case. The results allow us to conclude that adsorption is as useful as doping to tune the band gap in graphene enabling its applications in designing high performance electronic devices.

石墨烯具有完美的二维晶体结构，具有高比表面积、非凡的电学、热学和机械性能等诸多优异特性。然而，只有在这种无间隙半金属中诱导出所需值的带隙时，它才有可能在电子设备中使用。因此，已经进行了第一性原理计算以研究氧 (O) 掺杂对吸附的作用，以及杂质浓度和覆盖率以在 GGA 级别使用 PBE 的石墨烯中诱导带隙。由于空位的产生、氧的解离吸附、替代掺杂和预解离氧吸附而引起带隙。有趣的是，带隙是由 O 的掺杂和吸附过程引入的。氧掺杂导致两个能隙的感应，在费米能级以上值较小，在费米能级以下值较大；而无论吸附配置如何，吸附都会产生单一的直接间隙。在六边形掺杂浓度为 12.5% 的情况下（吸附情况除外），浓度和覆盖率的增加导致带隙值的最大值提高为 1.85 eV。结果使我们得出结论，吸附与掺​​杂一样有用，可以调节石墨烯的带隙，从而使其在设计高性能电子设备中得到应用。5% 浓度，吸附情况除外。结果使我们得出结论，吸附与掺​​杂一样有用，可以调节石墨烯的带隙，从而使其在设计高性能电子设备中得到应用。5% 浓度，吸附情况除外。结果使我们得出结论，吸附与掺​​杂一样有用，可以调节石墨烯的带隙，从而使其在设计高性能电子设备中得到应用。