Theoretical and experimental investigation on structural and electronic properties of Al/O/Al, O-doped WS2

•Investigation on structural and electronic properties of Al/O/Al, O-doped WS2.•The covalent character of the W–S bonding has been enhanced after doping.•Al and (Al, O)-doping both induce defect energy levels, causing p-type doping.•P-type doping has been verified by the binding energy moving to the low direction.

Effects of the doping atom (O, Al, and (Al, O)) on structural and electronic properties of the monolayer WS2 have been studied by using first-principles calculations. Results show that the covalent character of W–S bonding has been enhanced after doping. Meanwhile, W–O, Al–S and W–S bonds of (Al, O) co-doped WS2 monolayer have higher covalent character compared with O-doped and Al-doped WS2 monolayer of this work. After doping with Al (or Al, O) atoms, Fermi level moves close to the valence band and the dopant atoms produce the defect energy levels, indicating that Al doped and (Al, O) co-doped WS2 monolayer both have p-type conductivity. O-doped and (Al, O) co-doped WS2 ultrathin films was prepared on Si substrates. Results of Raman spectra show the formation of the O-doped and (Al, O) co-doped WS2 films. Moreover, compared with the pure WS2, the approximate reduction of 0.43 eV and 0.46 eV for W 4f and S 2p in binding energy after (Al, O) co-doped shows that p-type doping of (Al, O) co-doped WS2 has been verified.