Liu, HairuiGao, RuiYang, JienBanthia, Rohan DineshYang, FengWang, TianxingUpadhyaya, HariJain, Sagar M.2024-02-282024-02-282023-11-15Liu H, Gao R, Yang J, et al., (2023) Graphene-like dispersion and strong optical absorption in two-dimensional RP-type Sr3Ti2S7 perovskite. Crystal Growth & Design, Volume 23, Issue 12, November 2023, pp. 8575-85831528-7483https://doi.org/10.1021/acs.cgd.3c00608https://dspace.lib.cranfield.ac.uk/handle/1826/20896Two-dimensional (2D) Ruddlesden–Popper (RP) perovskite alloys have recently become attractive due to many desired physical properties originating from distinct van der Waals-type layered structures. In this work, a novel 2D RP-type Sr3Ti2S7 perovskite material design is proposed by using first-principles calculations. Our results reveal that the 2D Sr3Ti2S7 perovskite possesses dynamically stable structures, direct band structures with a band gap value of 0.86 eV, and a smaller effective mass (0.15/0.25 m0 for electron/hole) than MAPbI3 and phosphorene. More importantly, 2D Sr3Ti2S7 possesses wide optical spectra (from infrared-to ultraviolet-light region) and a higher absorption coefficient (105 cm–1) than MAPbI3, silicon, and MoS2 in the visible-light region. Interestingly, we also find that the ideal Dirac-like linear dispersion can appear near the Fermi level in the electronic band structures when compressive strain is applied. Especially, the Dirac-cone-like band structures can be realized when compressive strain is enhanced to −6%, indicating ultrahigh carrier mobility. These properties make the 2D Sr3Ti2S7 perovskite a promising candidate for future applications in solar cells and optoelectronic devices.enAttribution 4.0 InternationalArticle