Ab Initio Insights into Charge Localization in Bismuth Oxyhalides BiOX (X = F, Cl, Br, I)

Developing efficient photocatalysts for clean energy generation is crucial to achieving net-zero emissions. To this end, we investigate the behavior of photoexcited charges in bismuth oxyhalides BiOX (X = F, Cl, Br, and I), a family inexpensive promising photocatalysts. model localization excess electrons holes, use hybrid density functional theory PBE0(α). Our results indicate that electron polarons are unstable these materials. Concurrently, find hole favorable, identify two different possible configurations which formed. One consists dimerized halogen atoms (VK center) preferentially formed BiOBr BiOI with binding energies amount −0.26 −0.21 eV, respectively. The other corresponds on single Bi site surrounding oxygen (BiXO). This form polaron favorable BiOF BiOCl −0.35 −0.23 These findings highlight photogenerated carriers may open up avenues future investigations carrier transport oxyhalides.