Demir, Hilmi VolkanDelikanlı, SavaşCanımkurbey, BetülHernández-Martínez, P. L.Shabani, FarzanIşık, Ahmet TarıkÖzkan, İlaydaBozkaya, İklimBozkaya, TaylanIşık, FurkanDurmuşoglu, E. G.İzmir, M.Hakan, Akgün2024-03-122024-03-122023-05-090002-7863https://hdl.handle.net/11693/114630Solution-processed two-dimensional nanoplatelets (NPLs) allowing lateral growth of a shell (crown) by not affecting the pure confinement in the vertical direction provide unprecedented opportunities for designing heterostructures for light-emitting and -harvesting applications. Here, we present a pathway for designing and synthesizing colloidal type-II core/(multi-)crown hetero-NPLs and investigate their optical properties. Stoke's shifted broad photoluminescence (PL) emission and long PL lifetime (∼few 100 ns) together with our wavefunction calculations confirm the type-II electronic structure in the synthesized CdS/CdSe1-xTexcore/crown hetero-NPLs. In addition, we experimentally obtained the band-offsets between CdS, CdTe, and CdSe in these NPLs. These results helped us designing hetero-NPLs with near-unity PL quantum yield in the CdSe/CdSe1-xTex/CdSe/CdS core/multicrown architecture. These core/multicrown hetero-NPLs have two type-II interfaces unlike traditional type-II NPLs having only one and possess a CdS ending layer for passivation and efficient suppression of stacking required for optoelectronic applications. The light-emitting diode (LED) obtained using multicrown hetero-NPLs exhibits a maximum luminance of 36,612 cd/m2and external quantum efficiency of 9.3%, which outcompetes the previous best results from type-II NPL-based LEDs. These findings may enable designs of future advanced heterostructures of NPLs which are anticipated to show desirable results, especially for LED and lasing platforms. © 2023 American Chemical Society. All rights reserved.en-USCC BY 4.0 DEED (Attribution 4.0 International)https://creativecommons.org/licenses/by/4.0/Article10.1021/jacs.3c009991520-5126