First-principles study of the effects of Hf doping and different valence state O vacancies on the optoelectronic properties of SnO2

• Published in: Solid state communications Vol. 383; p. 115468
• Main Authors: Xia, Danyang, Fu, Rongpeng, Wang, Yuefei, Li, Bingsheng, Ma, Jiangang, Xu, Haiyang, Shen, Aidong, Liu, Yichun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2024
• Subjects: First principles; Formation energy of oxygen vacancy; HfxSn1-xO2; Rutile SnO2; Rutile SnO2; First principles; Formation energy of oxygen vacancy; HfxSn1-xO2
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2024.115468

The electronic structures of rutile-phase SnO2 with oxygen vacancies for different valence (VO0, VO1+, and VO2+) are studied using first-principles calculations. Under Sn-rich conditions, compared with VO1+, VO0,2+ shows a negative formation energy and VO2+ is the most stable. In addition, an increase in polarizability and an enhancement in visible light absorption are observed in the VO0 structure. To inhibit oxygen vacancies, the introduction of Hf ions as a dopant SnO2 is considered. Under Hf doping, the formation energy of oxygen vacancies is increased, indicating the inhibition of oxygen vacancies. Among the considered structures, Hf1Sn15O30 and Hf2Sn14O30 show the narrowest and widest bandgaps, respectively, resulting in blue shifts of the light absorption edges that extend the photoresponse range of the SnO2 material. •The O vacancies (VO0, VO1+, and VO2+) in the rutile SnO2 were constructed using first-principles calculations via density functional theory.•Under Sn-rich conditions, the formation energies of VO0/2+ are negative, and the formation energy of Vo2+ is lower than Vo0, both are more stable than VO1+.•To inhibit oxygen vacancies, Hf and oxygen vacancy doped system with different ratios (1:0, 1:1, 1:2, 2:0, 2:1, 2:2) are considered.•Among the calculated structures, Hf1Sn15O30 and Hf2Sn14O30 show the narrowest and widest band gap respectively.