TY - JOUR
T1 - Enhanced Near-Infrared-to-Visible Upconversion by Synthetic Control of PbS Nanocrystal Triplet Photosensitizers
AU - Huang, Zhiyuan
AU - Xu, Zihao
AU - Mahboub, Melika
AU - Liang, Zhiming
AU - Jaimes, Paulina
AU - Xia, Pan
AU - Graham, Kenneth R.
AU - Tang, Ming L.
AU - Lian, Tianquan
N1 - Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/6/26
Y1 - 2019/6/26
N2 - Photon upconversion employing semiconductor nanocrystals (NCs) makes use of their large and tunable absorption to harvest light in the near-infrared (NIR) wavelengths as well as their small gap between singlet and triplet excited states to reduce energy losses. Here, we report the highest QY (11.8%) thus far for the conversion of NIR to yellow photons by improving the quality of the PbS NC. This high QY was achieved by using highly purified lead and thiourea precursors. This QY is 2.6 times higher than from NCs prepared with commercially available lead and sulfide precursors. Transient absorption spectroscopy reveals two reasons for the enhanced QY: longer intrinsic exciton lifetimes of PbS NCs and the ability to support a longer triplet lifetime for the surface-bound transmitter molecule. Overall, this results in a higher efficiency of triplet exciton transfer from the PbS NC light absorber to the emitter and thus a higher photon upconversion QY.
AB - Photon upconversion employing semiconductor nanocrystals (NCs) makes use of their large and tunable absorption to harvest light in the near-infrared (NIR) wavelengths as well as their small gap between singlet and triplet excited states to reduce energy losses. Here, we report the highest QY (11.8%) thus far for the conversion of NIR to yellow photons by improving the quality of the PbS NC. This high QY was achieved by using highly purified lead and thiourea precursors. This QY is 2.6 times higher than from NCs prepared with commercially available lead and sulfide precursors. Transient absorption spectroscopy reveals two reasons for the enhanced QY: longer intrinsic exciton lifetimes of PbS NCs and the ability to support a longer triplet lifetime for the surface-bound transmitter molecule. Overall, this results in a higher efficiency of triplet exciton transfer from the PbS NC light absorber to the emitter and thus a higher photon upconversion QY.
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U2 - 10.1021/jacs.9b03385
DO - 10.1021/jacs.9b03385
M3 - Article
C2 - 31180212
AN - SCOPUS:85068105414
SN - 0002-7863
VL - 141
SP - 9769
EP - 9772
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 25
ER -