Revealing Excitonic and Electron-Hole Plasma States in Stimulated Emission of Single ${\mathrm{Cs}\mathrm{Pb}\mathrm{Br}}_{3}$ Nanowires at Room Temperature

Revealing Excitonic and Electron-Hole Plasma States in Stimulated Emission of Single ${Cs Pb Br}_{3}$ Nanowires at Room Temperature

Mai He, Ying Jiang, Qingbo Liu, Ziyu Luo, Chenxing Ouyang, Xiaoxia Wang, Weihao Zheng, Kai Braun, Alfred J. Meixner, Tingge Gao, Xiao Wang, and Anlian Pan

Phys. Rev. Applied 13, 044072 – Published 28 April 2020

Abstract

Nanostructured lead halide perovskites have received extensive attention due to their potential applications in integrated photonics. Despite many successful realizations of nanoscale coherent-light sources from lead halide perovskites, the role and interplay between excitonic and electron-hole plasma (EHP) states in the stimulated-emission process are not demonstrated yet. In this work, the carrier behavior and dynamics of the stimulated emission in ${Cs Pb Br}_{3}$ single nanowires are studied with a streak camera under power-dependent one-photon and two-photon excitation at room temperature. A redshift of the lasing gain profile with increasing excitation fluence is observed, suggesting the transition from the excitonic state to EHP state that is responsible for the lasing. Whereas, a blueshift of the gain profile with time decay represents the opposite direction of the former process. Moreover, the individual lasing modes show a blueshift as excitation fluence increases and a redshift as time elapses, due to the carrier-density dependence of the refractive index. This study could provide a comprehensive and deeper understanding of the carrier-density-driven stimulated-emission dynamics in lead halide nanowires and extend their applications in integrated photonics.

Received 19 October 2019
Revised 24 March 2020
Accepted 8 April 2020

DOI:https://doi.org/10.1103/PhysRevApplied.13.044072

Physics Subject Headings (PhySH)

Excitons Optoelectronics Upconversion

Nanowires Perovskites Semiconductor compounds

Femtosecond laser irradiation Time-resolved photoluminescence

Atomic, Molecular & OpticalCondensed Matter, Materials & Applied PhysicsNonlinear Dynamics

Authors & Affiliations

Mai He ¹, Ying Jiang¹, Qingbo Liu¹, Ziyu Luo², Chenxing Ouyang¹, Xiaoxia Wang¹, Weihao Zheng¹, Kai Braun³, Alfred J. Meixner³, Tingge Gao^4,5, Xiao Wang ^1,*, and Anlian Pan ^2,†

¹Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, Hunan University, Changsha 410012, China
²Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, Hunan University, Changsha 410012, China
³Institute of Physical and Theoretical Chemistry and LISA+, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
⁴Tianjin Key Laboratory of Molecular Optoelectronic Science, Institute of Molecular Plus, Tianjin University, Tianjin 300072, China
⁵Department of Physics, School of Science, Tianjin University, Tianjin 300072, China

^*xiao_wang@hnu.edu.cn
^†anlian.pan@hnu.edu.cn

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 13, Iss. 4 — April 2020

Subject Areas

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
(a) Streak-camera ima\-ges of the lasing emission from the ${Cs Pb Br}_{3}$ nanowire under 470-nm fs pulse laser excitation with different excitation fluences at room temperature. For each image, the whole vertical axis range corresponds to the time window of 40 ps. Five discrete lasing modes are labeled with A to E. Dashed lines indicate the positions of the initial peaks of modes B and C at the lowest excitation fluence. (b) Streak-camera image of the spontaneous emission from the ${Cs Pb Br}_{3}$ nanowire under 470-nm fs pulse laser excitation with an excitation fluence of 2.7 µJ cm⁻² at room temperature. The vertical axis range corresponds to the time window of 700 ps. The red curve shows the time-integrated PL spectrum over the time window. (c) Bright-field optical image of the investigated nanowire and the lasing emission from two ends under wide-field illumination. (d) Peak position of the lasing modes as a function of excitation fluence. The vertical bar of 1 meV is shared in all plots.
Reuse & Permissions
Figure 2
(a),(b) Time-resolved emission spectra with different time delays from the one-photon excited ${Cs Pb Br}_{3}$ nanowire under the excitation fluences of 15.7 and 26.4 µJ cm⁻². Solid lines are fitted spectra. Lasing modes are labeled (A, B, …) in the figures. Dashed arrows indicate the variation of emission peak position with time elapsed. (c) Peak position of the lasing modes as a function of time delay derived from (a) and (b). (d) Physical model of the interplay and reversible transitions between the excitonic and EHP states. E_g, band-gap energy; E_X, exciton energy; E_b, exciton-binding energy; and EHP, electron-hole plasma.
Reuse & Permissions
Figure 3
(a) Streak-camera images (with a time window of 25 ps) of the lasing emission from a two-photon (800 nm) pumped ${Cs Pb Br}_{3}$ nanowire with different excitation fluences at room temperature. Four discrete lasing modes labeled with A to D are observed. (b) Streak-camera image of the spontaneous emission from the ${Cs Pb Br}_{3}$ nanowire pumped at 800 nm with an excitation fluence of 42 µJ cm⁻² at room temperature. The vertical axis range corresponds to the time window of 700 ps. The red curve shows the time-integrated PL spectrum over the time window. (c) Bright-field optical image of the investigated nanowire with the lasing emission from the end faces under two-photon wide-field illumination. (d) Peak position of the lasing modes as a function of excitation fluence. The vertical bar of 2 meV is shared in all plots.
Reuse & Permissions
Figure 4
(a), (b) Time-resolved lasing emission spectra with different time delays from the two-photon (800 nm) excited ${Cs Pb Br}_{3}$ nanowire under the excitation fluences of 399 and 458 µJ cm⁻². (c) Peak position of the lasing modes A to D as a function of time delay derived from (a) and (b). (d) Peak position of the lasing modes B and C as a function of time delay under other excitation fluences.
Reuse & Permissions
Figure 5
(a)–(c) Emission intensity of different lasing modes for different excitation conditions as a function of time delay. Insets show respective streak-camera images with horizontal time axis and vertical photon-energy axis. For one-photon excitation with 18.2 µJ cm⁻² (a), all four lasing modes start and last for almost the same period of time. For one-photon excitation with a higher excitation fluence of 23 µJ cm⁻², the high-photon-energy mode B reaches its maximal intensity last, as indicated by the dashed arrows in (b). A clear trend with the low-photon-energy lasing mode starting first and high-photon-energy mode starting last is observed from the nanowire under two-photon excitation with excitation fluence of 458 µJ cm⁻² (c).
Reuse & Permissions

Physical Review Applied

Revealing Excitonic and Electron-Hole Plasma States in Stimulated Emission of Single CsPbBr3 Nanowires at Room Temperature

Mai He, Ying Jiang, Qingbo Liu, Ziyu Luo, Chenxing Ouyang, Xiaoxia Wang, Weihao Zheng, Kai Braun, Alfred J. Meixner, Tingge Gao, Xiao Wang, and Anlian Pan

Phys. Rev. Applied 13, 044072 – Published 28 April 2020

Abstract

Physics Subject Headings (PhySH)

Authors & Affiliations

Article Text (Subscription Required)

Supplemental Material (Subscription Required)

References (Subscription Required)

Issue

Subject Areas

Access Options

Authorization Required

Other Options

Download & Share

Images

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Log In

Search

Article Lookup

Paste a citation or DOI

Enter a citation

Revealing Excitonic and Electron-Hole Plasma States in Stimulated Emission of Single ${Cs Pb Br}_{3}$ Nanowires at Room Temperature