TY - JOUR
T1 - Resolving decay-time dependent photoluminescence induced by phonon-dressed excitons in ZnO
AU - Yukawa, Ryu
AU - Yamamoto, Susumu
AU - Arita, Ren
AU - Minami, Yuki
AU - Yamanoi, Kohei
AU - Ozawa, Kenichi
AU - Sakamoto, Kazuyuki
AU - Shimizu, Toshihiko
AU - Sarukura, Nobuhiko
AU - Matsuda, Iwao
N1 - Funding Information:
We are grateful to T. Sakurai for his help with the Hall measurements. This work was financially supported by Grants-in-Aid for Scientific Research (Grants No. 19H01830 and No. 22H01957) from the Japan Society for the Promotion of Science (JSPS) and by the Murata Science Foundation. The supporting experiments were carried out at SPring-8 BL07LSU of the Synchrotron Radiation Research Organization and at the Institute for Solid State Physics, The University of Tokyo.
Publisher Copyright:
© 2022 American Physical Society.
PY - 2022/10
Y1 - 2022/10
N2 - Time-resolved photoluminescence (PL) experiments on ZnO crystals have been conducted at room temperature to elucidate the origins of a near-band edge (NBE) emission. A temporal profile of the PL spectra exhibits a two-curve structure with different decaying rates and is reproduced reasonably by a biexponential function, indicating that there are at least two origins with different decay times in the NBE emission. By taking free exciton (FX)-longitudinal optical (LO) phonon interactions into account in the analysis of the PL spectra, the faster and slower decaying emissions are found to be associated with stronger and weaker FX-LO phonon coupling, respectively. We propose that the NBE emissions with different decay times are related to crystal imperfections; the fast-decaying emission originates from the region with a higher density of defects or impurities, while the slower one is from the regions with better crystallinity.
AB - Time-resolved photoluminescence (PL) experiments on ZnO crystals have been conducted at room temperature to elucidate the origins of a near-band edge (NBE) emission. A temporal profile of the PL spectra exhibits a two-curve structure with different decaying rates and is reproduced reasonably by a biexponential function, indicating that there are at least two origins with different decay times in the NBE emission. By taking free exciton (FX)-longitudinal optical (LO) phonon interactions into account in the analysis of the PL spectra, the faster and slower decaying emissions are found to be associated with stronger and weaker FX-LO phonon coupling, respectively. We propose that the NBE emissions with different decay times are related to crystal imperfections; the fast-decaying emission originates from the region with a higher density of defects or impurities, while the slower one is from the regions with better crystallinity.
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U2 - 10.1103/PhysRevMaterials.6.104607
DO - 10.1103/PhysRevMaterials.6.104607
M3 - Article
AN - SCOPUS:85141645824
SN - 2475-9953
VL - 6
JO - Physical Review Materials
JF - Physical Review Materials
IS - 10
M1 - 104607
ER -