TY - JOUR
T1 - Photoluminescence of Te-Doped Double Perovskite Cs2ZrCl6 Nanocrystals Versus Bulk
T2 - Insights From Temperature-Dependent Spectroscopy
AU - Liu, Yang
AU - Wu, Ye
AU - Sokolova, Anastasiia
AU - Shi, Xinmin
AU - Kershaw, Stephen V.
AU - Wu, Yusheng
AU - Polavarapu, Lakshminarayana
AU - Li, Xiaoming
AU - Rogach, Andrey L.
PY - 2025/7/29
Y1 - 2025/7/29
N2 - Although bulk crystals of lead-free vacancy-ordered double perovskites demonstrated a highly efficient emission, their nanocrystals (NCs) counterparts exhibit inferior optical performance. To understand the reasons behind this phenomenon, Cs2ZrCl6:Te4+ double perovskite NCs are synthesized, and their optical properties are compared with their bulk powders. Temperature-dependent spectroscopy revealed that the NCs sustain a thermal sensitization of the intermediate trap state, which is located between the self-trapped state of the host (Cs2ZrCl6) and the triplet states of the dopant (Te4+). This opens up a pathway for the non-radiative recombination, and thus decreases the energy transfer efficiency from host to dopant. Importantly, this pathway is suppressed in larger (40 nm) Cs2ZrCl6:Te4+ NCs, resulting in their photoluminescence quantum yield of 24%, as compared to 7% for the 22 nm NCs. Furthermore, the emission spectral range of these double perovskite NCs is shown to extended into near-infrared by incorporating rare-earth ions as additional dopants. The study has established a crucial relation between the optical properties and the size effect in lead-free vacancy-ordered double perovskites and thus lays a foundation for further improvement of their optical performance. © 2025 The Author(s). Small published by Wiley-VCH GmbH.
AB - Although bulk crystals of lead-free vacancy-ordered double perovskites demonstrated a highly efficient emission, their nanocrystals (NCs) counterparts exhibit inferior optical performance. To understand the reasons behind this phenomenon, Cs2ZrCl6:Te4+ double perovskite NCs are synthesized, and their optical properties are compared with their bulk powders. Temperature-dependent spectroscopy revealed that the NCs sustain a thermal sensitization of the intermediate trap state, which is located between the self-trapped state of the host (Cs2ZrCl6) and the triplet states of the dopant (Te4+). This opens up a pathway for the non-radiative recombination, and thus decreases the energy transfer efficiency from host to dopant. Importantly, this pathway is suppressed in larger (40 nm) Cs2ZrCl6:Te4+ NCs, resulting in their photoluminescence quantum yield of 24%, as compared to 7% for the 22 nm NCs. Furthermore, the emission spectral range of these double perovskite NCs is shown to extended into near-infrared by incorporating rare-earth ions as additional dopants. The study has established a crucial relation between the optical properties and the size effect in lead-free vacancy-ordered double perovskites and thus lays a foundation for further improvement of their optical performance. © 2025 The Author(s). Small published by Wiley-VCH GmbH.
KW - double perovskites
KW - energy transfer
KW - nanocrystals
KW - optical properties
KW - rare-earth ion doping
UR - https://www.scopus.com/pages/publications/105003818383
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-105003818383&origin=recordpage
U2 - 10.1002/smll.202501342
DO - 10.1002/smll.202501342
M3 - RGC 21 - Publication in refereed journal
C2 - 40270307
SN - 1613-6810
VL - 21
JO - Small
JF - Small
IS - 30
M1 - 2501342
ER -