Colloidal Spherical Quantum Wells with Near-Unity Photoluminescence Quantum Yield and Suppressed Blinking.
Thick inorganic shells endow colloidal nanocrystals (NCs) with enhanced photochemical stability and suppression of photoluminescence intermittency (also known as blinking). However, the progress of using thick-shell heterostructure NCs in applications has been limited due to the low photoluminescence quantum yield (PL QY ≤ 60%) at room temperature. Here, we demonstrate thick-shell NCs with CdS/CdSe/CdS seed/spherical quantum well/shell (SQW) geometry that exhibit near-unity PL QY at room temperature and suppression of blinking. In SQW NCs, the lattice mismatch is diminished between the emissive CdSe layer and the surrounding CdS layers as a result of coherent strain, which suppresses the formation of misfit defects and consequently permits ∼100% PL QY for SQW NCs with a thick CdS shell (≥5 nm). High PL QY of thick-shell SQW NCs is preserved even in concentrated dispersion and in film under thermal stress, which makes them promising candidates for applications in solid-state lightings and luminescent solar concentrators.
Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
Byeong Guk
BG
Jeong
Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.|Center for High Technology Materials, University of New Mexico , Albuquerque, New Mexico 87131, United States.
Young-Shin
YS
Park
School of Chemical and Biological Engineering, The National Creative Research Initiative Center for Intelligent Hybrids, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Jun Hyuk
JH
Chang
Department of Chemical and Biological Engineering, Korea University , 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
Ikjun
I
Cho
Photoelectronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , 14-gil 5 Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea.
Jai Kyeong
JK
Kim
Photoelectronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , 14-gil 5 Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea.
Heesuk
H
Kim
School of Chemical and Biological Engineering, The National Creative Research Initiative Center for Intelligent Hybrids, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Kookheon
K
Char
Department of Chemical and Biological Engineering, Korea University , 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
Jinhan
J
Cho
Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
Victor I
VI
Klimov
Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States.
Philip
P
Park
Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
Doh C
DC
Lee
Photoelectronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , 14-gil 5 Hwarang-ro, Seongbuk-gu, Seoul 02792, Republic of Korea.
Wan Ki
WK
Bae
coherently strained heterostructure; critical thickness; misfit defect; near-unity photoluminescence quantum yield; spherical quantum well