Combining two-photon photoemission and transient absorption spectroscopy to resolve hot carrier cooling in 2D perovskite single crystals: the effect of surface layer. Issue 44 (31st October 2022)

• Record Type: Journal Article
• Authors: Lin, Weihua; Liang, Mingli; Niu, Yuran; Chen, Zhesheng; Cherasse, Marie; Meng, Jie; Zou, Xianshao; Zhao, Qian; Geng, Huifang; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Canton, Sophie E.; Zheng, Kaibo; Pullerits, Tönu
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 44(2022)
• Page Start: 16751
• Page End: 16760
• Publication Date: 2022-10-31
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc03111f
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : We investigate HC cooling in two-dimensional perovskite single-crystals by applying two complementary ultrafast techniques and observe spatial sensitivity of cooling. Abstract : We investigate hot carrier (HC) cooling in two-dimensional (2D) perovskite single crystals by applying two complementary ultrafast spectroscopy techniques – transient absorption (TA) and time-resolved two-photon photoemission (TR-2PPE) spectroscopies. TR-2PPE directly maps the hot electron distribution and its dynamics in the conduction band to the detected photoelectron distribution. While TR-2PPE selectively probes the upper layer of the material, TA provides information on the whole bulk. Two cooling regimes are resolved in both techniques. The fast timescale of 100–200 fs is related to the electron scattering by longitudinal optical (LO) phonons and the slow timescale of 3–4 ps corresponds to the LO phonon relaxation. The HC cooling dynamic of TA measurement has faster initial stage and higher starting temperature for the slower stage than in TR-2PPE measurements. Conclusions about spatial sensitivity of the cooling dynamics across the 2D perovskite single crystals constitute valuable information that can guide the future development of HC solar cells and thermoelectric applications based on 2D perovskites.