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Lifting restrictions on coherence loss when characterizing non-transparent hypersonic phononic crystals. Sci Rep 2021; 11:17174. [PMID: 34433886 PMCID: PMC8387379 DOI: 10.1038/s41598-021-96663-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/10/2021] [Indexed: 11/09/2022] Open
Abstract
Hypersonic phononic bandgap structures confine acoustic vibrations whose wavelength is commensurate with that of light, and have been studied using either time- or frequency-domain optical spectroscopy. Pulsed pump-probe lasers are the preferred instruments for characterizing periodic multilayer stacks from common vacuum deposition techniques, but the detection mechanism requires the injected sound wave to maintain coherence during propagation. Beyond acoustic Bragg mirrors, frequency-domain studies using a tandem Fabry–Perot interferometer (TFPI) find dispersions of two- and three-dimensional phononic crystals (PnCs) even for highly disordered samples, but with the caveat that PnCs must be transparent. Here, we demonstrate a hybrid technique for overcoming the limitations that time- and frequency-domain approaches exhibit separately. Accordingly, we inject coherent phonons into a non-transparent PnC using a pulsed laser and acquire the acoustic transmission spectrum on a TFPI, where pumped appear alongside spontaneously excited (i.e. incoherent) phonons. Choosing a metallic Bragg mirror for illustration, we determine the bandgap and compare with conventional time-domain spectroscopy, finding resolution of the hybrid approach to match that of a state-of-the-art asynchronous optical sampling setup. Thus, the hybrid pump–probe technique retains key performance features of the established one and going forward will likely be preferred for disordered samples.
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Mante PA, Stoumpos CC, Kanatzidis MG, Yartsev A. Electron-acoustic phonon coupling in single crystal CH 3NH 3PbI 3 perovskites revealed by coherent acoustic phonons. Nat Commun 2017; 8:14398. [PMID: 28176755 PMCID: PMC5309855 DOI: 10.1038/ncomms14398] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/21/2016] [Indexed: 12/03/2022] Open
Abstract
Despite the great amount of attention CH3NH3PbI3 has received for its solar cell application, intrinsic properties of this material are still largely unknown. Mobility of charges is a quintessential property in this aspect; however, there is still no clear understanding of electron transport, as reported values span over three orders of magnitude. Here we develop a method to measure the electron and hole deformation potentials using coherent acoustic phonons generated by femtosecond laser pulses. We apply this method to characterize a CH3NH3PbI3 single crystal. We measure the acoustic phonon properties and characterize electron-acoustic phonon scattering. Then, using the deformation potential theory, we calculate the carrier intrinsic mobility and compare it to the reported experimental and theoretical values. Our results reveal high electron and hole mobilities of 2,800 and 9,400 cm2 V−1 s−1, respectively. Comparison with literature values of mobility demonstrates the potential role played by polarons in charge transport in CH3NH3PbI3. Carrier mobility is a basic semiconductor property. Mante et al., use femtosecond lasers to investigate coherent acoustic phonons and relate their deformation potentials to estimate the intrinsic electron and hole mobilities of CH3NH3PbI3 single crystals to be 2,800 and 9,400 cm2 V−1 s−1, respectively.
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Affiliation(s)
- Pierre-Adrien Mante
- Division of Chemical Physics, Department of Chemistry and NanoLund, Lund University, 221 00 Lund, Sweden
| | | | | | - Arkady Yartsev
- Division of Chemical Physics, Department of Chemistry and NanoLund, Lund University, 221 00 Lund, Sweden
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THz Acoustic Spectroscopy by using Double Quantum Wells and Ultrafast Optical Spectroscopy. Sci Rep 2016; 6:28577. [PMID: 27346494 PMCID: PMC4921868 DOI: 10.1038/srep28577] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/06/2016] [Indexed: 12/02/2022] Open
Abstract
GaN is a pivotal material for acoustic transducers and acoustic spectroscopy in the THz regime, but its THz phonon properties have not been experimentally and comprehensively studied. In this report, we demonstrate how to use double quantum wells as a THz acoustic transducer for measuring generated acoustic phonons and deriving a broadband acoustic spectrum with continuous frequencies. We experimentally investigated the sub-THz frequency dependence of acoustic attenuation (i.e., phonon mean-free paths) in GaN, in addition to its physical origins such as anharmonic scattering, defect scattering, and boundary scattering. A new upper limit of attenuation caused by anharmonic scattering, which is lower than previously reported values, was obtained. Our results should be noteworthy for THz acoustic spectroscopy and for gaining a fundamental understanding of heat conduction.
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Mante PA, Huang YR, Yang SC, Liu TM, Maznev AA, Sheu JK, Sun CK. THz acoustic phonon spectroscopy and nanoscopy by using piezoelectric semiconductor heterostructures. ULTRASONICS 2015; 56:52-65. [PMID: 25455189 DOI: 10.1016/j.ultras.2014.09.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 09/18/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
Thanks to ultrafast acoustics, a better understanding of acoustic dynamics on a short time scale has been obtained and new characterization methods at the nanoscale have been developed. Among the materials that were studied during the development of ultrafast acoustics, nitride based heterostructures play a particular role due to their piezoelectric properties and the possibility to generate phonons with over-THz frequency and bandwidth. Here, we review some of the work performed using this type of structure, with a focus on THz phonon spectroscopy and nanoscopy. First, we present a brief description of the theory of coherent acoustic phonon generation by piezoelectric heterostructure. Then the first experimental observation of coherent acoustic phonon generated by the absorption of ultrashort light pulses in piezoelectric heterostructures is presented. From this starting point, we then present some methods developed to realize customizable phonon generation. Finally we review some more recent applications of these structures, including imaging with a nanometer resolution, broadband attenuation measurements with a frequency up to 1THz and phononic bandgap characterization.
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Affiliation(s)
- Pierre-Adrien Mante
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Yu-Ru Huang
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Szu-Chi Yang
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Tzu-Ming Liu
- Institute of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Alexei A Maznev
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jinn-Kong Sheu
- Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan
| | - Chi-Kuang Sun
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan; Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan; Institute of Physics and Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan.
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Mante PA, Chen CC, Wen YC, Chen HY, Yang SC, Huang YR, Chen IJ, Chen YW, Gusev V, Chen MJ, Kuo JL, Sheu JK, Sun CK. Probing hydrophilic interface of solid/liquid-water by nanoultrasonics. Sci Rep 2014; 4:6249. [PMID: 25176017 PMCID: PMC4150100 DOI: 10.1038/srep06249] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 08/12/2014] [Indexed: 11/24/2022] Open
Abstract
Despite the numerous devoted studies, water at solid interfaces remains puzzling. An ongoing debate concerns the nature of interfacial water at a hydrophilic surface, whether it is more solid-like, ice-like, or liquid-like. To answer this question, a complete picture of the distribution of the water molecule structure and molecular interactions has to be obtained in a non-invasive way and on an ultrafast time scale. We developed a new experimental technique that extends the classical acoustic technique to the molecular level. Using nanoacoustic waves with a femtosecond pulsewidth and an ångström resolution to noninvasively diagnose the hydration structure distribution at ambient solid/water interface, we performed a complete mapping of the viscoelastic properties and of the density in the whole interfacial water region at hydrophilic surfaces. Our results suggest that water in the interfacial region possesses mixed properties and that the different pictures obtained up to now can be unified. Moreover, we discuss the effect of the interfacial water structure on the abnormal thermal transport properties of solid/liquid interfaces.
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Affiliation(s)
- Pierre-Adrien Mante
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chien-Cheng Chen
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Yu-Chieh Wen
- 1] Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan [2] Institute of Physics and Research Center for Applied Science, Academia Sinica, Taipei 115, Taiwan
| | - Hui-Yuan Chen
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Szu-Chi Yang
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Yu-Ru Huang
- Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan
| | - I-Ju Chen
- Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Wen Chen
- Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
| | - Vitalyi Gusev
- Laboratoire d'Acoustique, LAUM, UMR No. 6613 associée au CNRS, LUNAM Université, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans, France
| | - Miin-Jang Chen
- Department of Material Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
| | - Jinn-Kong Sheu
- Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan
| | - Chi-Kuang Sun
- 1] Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan [2] Institute of Physics and Research Center for Applied Science, Academia Sinica, Taipei 115, Taiwan [3] Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan [4] Graduate Institute of Biomedical Electronics and Bioinformatics and Center for Optoelectronics Medicine, National Taiwan University, Taipei 10617, Taiwan
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