The Electronic Structure of N-doped ZnO Calculated by First Principle Calculation

Abstract

To improve photocatalytic performance of any element or compound, its electronic structure will be modified. In this work, ZnO structure is modified by N doping. Because there are experimental researches reported that N-doped ZnO shows higher photocatalytic activity than pure ZnO. Zinc oxide and nitrogen-doped zinc oxide were calculated and investigated electronic structure via density of states (DOS) and band structures. The calculation was carried out by density functional theory (DFT) using Vienna Ab initio Simulation Package (VASP) code. GGA+U is employed to describe exchange-correlation potential of the simulation. The calculated electronic structure of nitrogen doping in zinc oxide shows appreciate electronic structure, occurring new states at the top of valence band and being narrower of E_g from 2.24 eV of direct band gap to 1.92 eV. Also, p-type characteristic of dopant system is observed from shifting of Fermi level to lower energy near valence states. Being narrower of band gap suggests that ZnO can photocatalytic degrade under visible range. It suggests that N-doped ZnO can improve photocatalytic performance of ZnO. Also, nitrogen doping could turn n-type zinc oxide into p-type material for more applications.