TY - JOUR
T1 - CdSe/CdS/CdTe Core/Barrier/Crown Nanoplatelets
T2 - Synthesis, Optoelectronic Properties, and Multiphoton Fluorescence Upconversion
AU - Khan, Ali Hossain
AU - Bertrand, Guillaume H V
AU - Teitelboim, Ayelet
AU - Sekhar M, Chandra
AU - Polovitsyn, Anatolii
AU - Brescia, Rosaria
AU - Planelles, Josep
AU - Climente, Juan Ignacio
AU - Oron, Dan
AU - Moreels, Iwan
N1 - The present publication is realized with the support of the Ministero degli Affari Esteri e della Cooperazione Internazionale and the Ministry of Science, Technology and Space of the state of Israel (IONX-NC4SOL), and by the Crown Photonics Center of the Weizmann Institute of Science. This project has also received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 714876 PHOCONA). J.C. and J.P. acknowledge the support from MINECO (project CTQ2017-83781-P) and UJI (project B2017-59). We also acknowledge the TEM facility of the Nematology Research Unit, member of the UGent TEM-Expertise center (life sciences).
PY - 2020/4/28
Y1 - 2020/4/28
N2 - Colloidal two-dimensional (2D) nanoplatelet heterostructures are particularly interesting as they combine strong confinement of excitons in 2D materials with a wide range of possible semiconductor junctions due to a template-free, solution-based growth. Here, we present the synthesis of a ternary 2D architecture consisting of a core of CdSe, laterally encapsulated by a type-I barrier of CdS, and finally a type-II outer layer of CdTe as so-called crown. The CdS acts as a tunneling barrier between CdSe- and CdTe-localized hole states, and through strain at the CdS/CdTe interface, it can induce a shallow electron barrier for CdTe-localized electrons as well. Consequently, next to an extended fluorescence lifetime, the barrier also yields emission from CdSe and CdTe direct transitions. The core/barrier/crown configuration further enables two-photon fluorescence upconversion and, due to a high nonlinear absorption cross section, even allows to upconvert three near-infrared photons into a single green photon. These results demonstrate the capability of 2D heterostructured nanoplatelets to combine weak and strong confinement regimes to engineer their optoelectronic properties.
AB - Colloidal two-dimensional (2D) nanoplatelet heterostructures are particularly interesting as they combine strong confinement of excitons in 2D materials with a wide range of possible semiconductor junctions due to a template-free, solution-based growth. Here, we present the synthesis of a ternary 2D architecture consisting of a core of CdSe, laterally encapsulated by a type-I barrier of CdS, and finally a type-II outer layer of CdTe as so-called crown. The CdS acts as a tunneling barrier between CdSe- and CdTe-localized hole states, and through strain at the CdS/CdTe interface, it can induce a shallow electron barrier for CdTe-localized electrons as well. Consequently, next to an extended fluorescence lifetime, the barrier also yields emission from CdSe and CdTe direct transitions. The core/barrier/crown configuration further enables two-photon fluorescence upconversion and, due to a high nonlinear absorption cross section, even allows to upconvert three near-infrared photons into a single green photon. These results demonstrate the capability of 2D heterostructured nanoplatelets to combine weak and strong confinement regimes to engineer their optoelectronic properties.
UR - http://www.scopus.com/inward/record.url?scp=85084167896&partnerID=8YFLogxK
U2 - 10.1021/acsnano.9b09147
DO - 10.1021/acsnano.9b09147
M3 - مقالة
C2 - 32275814
SN - 1936-0851
VL - 14
SP - 4206
EP - 4215
JO - ACS Nano
JF - ACS Nano
IS - 4
ER -