Band-Edge Exciton Fine Structure and Exciton Recombination Dynamics in Single Crystals of Layered Hybrid PerovskitesFang, H-H., Yang, J., Adjokatse, S., Tekelenburg, E., Kamminga, M. E., Duim, H., Ye, J., Blake, G. R., Even, J. & Loi, M. A., 5-Feb-2020, In : Advanced Functional Materials. 30, 6, 9 p., 1907979.
Research output: Contribution to journal › Article › Academic › peer-review
2D perovskite materials have recently reattracted intense research interest for applications in photovoltaics and optoelectronics. As a consequence of the dielectric and quantum confinement effect, they show strongly bound and stable excitons at room temperature. Here, the band-edge exciton fine structure and in particular its exciton and biexciton dynamics in high quality crystals of (PEA)2PbI4 are investigated. A comparison of bulk and surface exciton lifetimes yields a room temperature surface recombination velocity of 2 × 103 cm s−1 and an intrinsic lifetime of 185 ns. Biexciton emission is evidenced at room temperature, with a binding energy of ≈45 meV and a lifetime of 80 ps. At low temperature, exciton state splitting is observed, which is caused by the electron–hole exchange interaction. Transient photoluminescence resolves the low-lying dark exciton state, with a bright/dark splitting energy estimated to be 10 meV. This work contributes to the understanding of the complex scenario of the elementary photoexcitations in 2D perovskites.
|Number of pages||9|
|Journal||Advanced Functional Materials|
|Early online date||9-Dec-2019|
|Publication status||Published - 5-Feb-2020|
- biexciton, dark exciton, exciton state splitting, layered perovskite, ultrafast dynamics, CHARGED EXCITONS, BINDING-ENERGY, BIEXCITONS, NANOCRYSTALS, PHOTOLUMINESCENCE, EMISSION, STATES