Enhancing two-dimensional electronic spectroscopy for layered halide perovskites

• Main Authors: Ramesh, Sankaran, Feng, Minjun, Furuhashi, Tomoki, Sum, Tze Chien
• Other Authors: Interdisciplinary Graduate School (IGS)
• Format: Article
• Language: English
• Published: 2023
• Subjects: Physics; Ruddlesden−popper; Delocalization; Spacer cation; Supercontinuum; Pulse shaper; Hollow-core fiber
• Online Access: https://hdl.handle.net/10356/172521
• Institution: Nanyang Technological University

The photophysics of layered halide perovskites reveals a rich disposition of exciton behavior. Two-dimensional electronic spectroscopy (2DES) is a powerful technique for investigating such excitonic interactions and dynamics. However, the wide spectral range of layered perovskites presents a challenge in studies utilizing conventional 2DES setups to simultaneously probe their interacting excitonic states. Herein, we put forward a versatile 2DES setup employing a hollow-core fiber compressor (HCFC) to generate stable and optimized broadband laser pulses (6 fs) covering a spectral range of 500–950 nm. 2D spectra with high temporal and spectral resolution are possible even with a pulse-shaper-based commercial 2DES setup. Application to a representative two-phase Ruddlesden–Popper perovskite thin film reveals well-defined signals at the diagonal and off-diagonal positions, indicative of exciton delocalization between the two transitions. Our straightforward modification of a commercial 2DES setup extends its capabilities to investigate the large family of layered perovskites currently under intense scrutiny in the development of perovskite optoelectronics.