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Full-Text Articles in Physics
Electrical And Optical Characterization Of Two-Dimensional Semiconductors Using Ultrafast Spectroscopy, Pan Adhikari
Electrical And Optical Characterization Of Two-Dimensional Semiconductors Using Ultrafast Spectroscopy, Pan Adhikari
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The emergence of two-dimensional (2D) layered materials provides unprecedented opportunities for studying excitonic physics due to the strong Coulomb interaction between the electron-hole pair. Because of the reduced dimensionality and weak dielectric screening, the exciton is stable at room temperature, unlike bulk semiconductors. The evolution from low to high carrier density for optical gain in 2D semiconductors involves insulating exciton gas, exciton condensation, co-existence of various excitonic complexes, electron-hole plasmas (EHPs), or electron-hole liquids (EHLs), leading to the Mott transition. Strong interaction among the excitons, such as exciton-exciton annihilation (EEA), serves as a hot-carrier generation. A bound exciton dissociates into …
In Situ Study Of Ultrafast Carrier Transport Dynamics In Perovskite Thin-Films, Kanishka Kobbekaduwa
In Situ Study Of Ultrafast Carrier Transport Dynamics In Perovskite Thin-Films, Kanishka Kobbekaduwa
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Perovskites are a novel class of materials that have piqued the interest of researchers in photovoltaics, photodetectors, and optoelectronics. In this study, we measure and elucidate in situ ultrafast carrier dynamics in both organic and inorganic, lead, and non-lead-based halide perovskite thin films using ultrafast photocurrent spectroscopy (UPCS) with a sub-25 ps time resolution. The UPCS technique enables us to define carrier transport dynamics in spatial, temporal, and energy landscapes via measurements at different electric fields, laser intensities, and temperatures. Here we explore and analyze solution-processed bulk MAPbI3 and nanocrystalline CsPbI3-based devices and novel non-lead double-layered perovskite …