Contact

Additional Info

  • Mail Code: 5080

All Publications

  • Twisted Tin-Chloride Perovskite Single-Crystal Heterostructures. Angewandte Chemie (International ed. in English) Cleron, J. L., Chen, C. Y., Pan, F., Saha, S., Marlton, F. P., Stolz, R. M., Li, J., Dionne, J. A., Liu, F., Filip, M. R., Karunadasa, H. I. 2025: e20140

    Abstract

    Self-assembly affords simpler synthetic routes to heterostructures compared with manual layer-by-layer stacking, yet controlling interlayer twist angles in a bulk solid remains an outstanding challenge. We report two new single-crystal heterostructures: (Sn2Cl2)(CYS)2SnCl4 (CYS = +NH3(CH2)2S-; Sn_CYS) and (Sn2Cl2)(SeCYS)2SnCl4 (SeCYS = +NH3(CH2)2Se-; Sn_SeCYS) synthesized in solution, with alternating perovskite and intergrowth layers. Notably, compared to the recently reported lead analog, (Pb2Cl2)(CYS)2PbCl4 (Pb_CYS), the tin heterostructures feature a twist between the perovskite and intergrowth layers. We trace this twist to local distortions at the Sn centers, which change the interfacial lattice-matching requirements compared to those of the Pb analog. Electronic band structure calculations show that the striking differences in the relative energies of perovskite- and intergrowth-derived bands in Sn_CYS and Pb_CYS arise from structural and not compositional differences. The structural anisotropy of Sn_CYS is also reflected in a large in-plane photoluminescence linear anisotropy ratio. Interfacial strain further affords differential incorporation of Pb into the perovskite and intergrowth layers of the Sn heterostructures, resulting in redshifted optical absorption onsets. Thus, we posit that local structural distortions may be exploited to manipulate the twist angle and interfacial strain in bulk heterostructures, providing a new handle for tuning the band alignments of bulk quantum-well electronic structures.

    View details for DOI 10.1002/anie.202520140

    View details for PubMedID 41414937

  • Tuning the Quantum-Well Structure of Single-Crystal Layered Perovskite Heterostructures. Journal of the American Chemical Society Deshmukh, A. P., Chen, Y., Cleron, J. L., Tie, M., Wen, J., Heinz, T. F., Filip, M. R., Karunadasa, H. I. 2025

    Abstract

    Single-crystal layered perovskite heterostructures provide a scalable platform for potentially realizing emergent properties recently seen in mechanically stacked monolayers. We report two new layered perovskite heterostructures M2(PbCl2)(AMCHC)2(PbCl4)·2H2O (1_M where M = Na+, Li+; AMCHC = +NH3CH2C6H10COO-) crystallizing in the chiral, polar space group C2. The heterostructures exhibit alternating layers of a lead-chloride perovskite and an intergrowth comprising corner-sharing PbCl4(η2-COO)2 polyhedra with bridging equatorial chlorides and terminal axial oxygen ligands. Small alkali metal cations and water molecules occupy the cavities between the polyhedra in the intergrowth layer. The heterostructures display wide bandgaps, two closely spaced excitonic features in their optical spectra, and strong second harmonic generation. The calculated band structure of 1_Na features a Type-I quantum-well structure, where the electron-hole correlation function corresponding to the lowest excited state points to electron-hole pairs localized within a single inorganic layer (intralayer excitons), as seen in typical layered halide perovskites. In contrast, calculations show that 1_Li adopts a Type-II quantum-well structure, with electrons and holes in the lowest excited state residing in different inorganic layers (interlayer excitons). Calculations on model complexes suggest that these changes in band alignment, between Type-I and Type-II quantum-well structures, are driven by the placement of the alkali metal and the orientation of the water molecules, changing the electrostatic potential-energy profiles of the heterostructures. Thus, this study sets the stage for accessing different alignments of the perovskite and intergrowth bands in bulk perovskite heterostructures that self-assemble in solution.

    View details for DOI 10.1021/jacs.5c08391

    View details for PubMedID 41133977