Effects of Chlorine Mixing on Optoelectronics, Ion-Migration and Gamma-ray Detection In Bromide Perovskites

Nikita Rybin (1) , Dibyajyoti Ghosh (2) , Jeremy Tisdale (2) , Shreetu Shrestha (2) , Michael Yoho (2) , Duc Duy Vo (2) , Jacky Even (3) , Claudine Katan (4) , Wanyi Nie (2) , Amanda J Neukirch (2) , Sergei Tretiak (2)

1 Skoltech - Skolkovo Institute of Science and Technology [Moscow]
2 LANL - Los Alamos National Laboratory
3 FOTON - Institut des Fonctions Optiques pour les Technologies de l'informatiON
4 ISCR - Institut des Sciences Chimiques de Rennes

Controlled anion-mixing in halide perovskites has been shown to be an effective route to precisely tuning optoelectronic properties, in order to achieve efficient photo- voltaic, light emission and radiation detection devices. However, an atomistic under- standing behind the precise mechanism impacting the performances of mixed halide perovskite devices, particularly as a radiation detector, is still missing. Combining high-level computational methods and multiple experiments, here we systematically investigate the effect of chlorine (Cl) incorporation on the optical and electronic prop- erties, structural stability, ion-migration as well as the γ-ray radiation detection ability of MAPbBr 3-x Cl x . We observe that precise halide mixing suppresses bromide ion mi- gration and consequently reduces the dark current by close to a factor of two, which significantly improves the resistance of the mixed-anion devices. Furthermore, reduced carrier effective masses and mostly unchanged exciton binding energies indicate en- hanced charge carrier transport for these perovskite alloys. At the atomistic level, modifications to ion migration and charge carrier transport properties improve elec- tronic properties and predominantly contribute to the better response and resolution in high-energy γ-ray detection with MAPbBr 3-x Cl x , as compared to MAPbBr 3 . This study provides a systematic approach to enhance the high-energy radiation detection ability of MAPbBr 3-x Cl x -based devices by understanding the atomistic properties un- derpinning performance.

Domaines: Matériaux

Nikita Rybin, Dibyajyoti Ghosh, Jeremy Tisdale, Shreetu Shrestha, Michael Yoho, et al.. Effects of Chlorine Mixing on Optoelectronics, Ion-Migration and Gamma-ray Detection In Bromide Perovskites. Chemistry of Materials, 2020, 32 (5), pp.1854-1863. ⟨10.1021/acs.chemmater.9b04244⟩. ⟨hal-02478539⟩