The optoelectronic properties of layered α-MoO3 are greatly limited due to its wide band gap and low carrier concentration. The insertion of hydrogen (H) can effectively tune the band structure and carrier concentration of MoO3. Herein, first-principles calculations were performed to unravel the physical mechanism of a H-doped α-MoO3 system. We found that the modulation of the electronic structure of H-doped MoO3 depends on the doping concentration and position of the H atoms. It was found that the band gap decreases at 8% doping concentration due to the strong coupling between Mo-4d and O-2p orbits when H atoms are inserted into the interlayer. More interestingly, the band gap decreases to an extreme due to the Mo-4d orbit when all the H atoms are inserted into the intralayer only, which has a remarkable effect on light absorption. Our research provides a comprehensive theoretical discussion on the mechanism of H-doped α-MoO3 from the doping positions and doping concentrations, and offers useful strategies on doping modulation of the photoelectric properties of layered transition metal oxides.
Keywords: H doping modulation; Insertion; layer structure; optoelectronic properties; α-MoO3.