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Duan J, Wang J, Hou L, Ji P, Zhang W, Liu J, Zhu X, Sun Z, Ma Y, Ma L. Application of Scanning Tunneling Microscopy and Spectroscopy in the Studies of Colloidal Quantum Qots. CHEM REC 2023; 23:e202300120. [PMID: 37255365 DOI: 10.1002/tcr.202300120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/15/2023] [Indexed: 06/01/2023]
Abstract
Colloidal quantum dots display remarkable optical and electrical characteristics with the potential for extensive applications in contemporary nanotechnology. As an ideal instrument for examining surface topography and local density of states (LDOS) at an atomic scale, scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) has become indispensable approaches to gain better understanding of their physical properties. This article presents a comprehensive review of the research advancements in measuring the electronic orbits and corresponding energy levels of colloidal quantum dots in various systems using STM and STS. The first three sections introduce the basic principles of colloidal quantum dots synthesis and the fundamental methodology of STM research on quantum dots. The fourth section explores the latest progress in the application of STM for colloidal quantum dot studies. Finally, a summary and prospective is presented.
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Affiliation(s)
- Jiaying Duan
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Jiapeng Wang
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Liangpeng Hou
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Peixuan Ji
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Wusheng Zhang
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Jin Liu
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Xiaodong Zhu
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Zhixiang Sun
- Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin, China, 300072
| | - Yanqing Ma
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
| | - Lei Ma
- Tianjin International Center for Nanoparticles and NanoSystems, Tianjin University, Tianjin, China, 300072
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Mishra L, Kumar A, Panigrahi A, Dubey P, Dutta S, Parida P, Sarangi MK. Unraveling the Relevance of Electron and Hole Transfer in Lead Halide Perovskite Nanocrystals on Current Conduction. J Phys Chem Lett 2023; 14:7340-7345. [PMID: 37561565 DOI: 10.1021/acs.jpclett.3c01893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Optimization of perovskite-based optoelectronic performance demands prudent engineering in the device architecture with facile transport of generated charge carriers. Herein, we explore the charge transfer (CT) kinetics in perovskite nanocrystals (PNCs), CsPbBr3, with two redox-active quinones, menadione (MD) and anthraquinone (AQ), and its alteration in halide exchanged CsPbCl3. With a series of spectroscopic and microscopic measurements, we infer that both electron and hole transfer (ET-HT) prevail in CsPbCl3 with quinones, resulting in a faster CT, while ET predominates for CsPbBr3. Furthermore, current-sensing atomic force microscopy measurements demonstrate that the conductance across a metal-PNC-metal nanojunction is improved in the presence of quinones. The contributions of ET and HT to current conduction across PNCs are well supported and validated by theoretical calculations of the density of states. These outcomes convey a new perspective on the relevance of ET and HT in the optimal current conduction and optoelectronic device engineering of perovskites.
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Affiliation(s)
- Leepsa Mishra
- Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106
| | - Ajay Kumar
- Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106
| | - Aradhana Panigrahi
- Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106
| | - Priyanka Dubey
- Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106
| | - Soumi Dutta
- Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106
| | - Prakash Parida
- Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106
| | - Manas Kumar Sarangi
- Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106
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Basu TS, Diesch S, Hayakawa R, Wakayama Y, Scheer E. Single-charge transport through hybrid core-shell Au-ZnS quantum dots: a comprehensive analysis from a modified energy structure. NANOSCALE 2021; 13:4978-4984. [PMID: 33634301 DOI: 10.1039/d0nr06883g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We examined the modified electronic structure and single-carrier transport of individual hybrid core-shell metal-semiconductor Au-ZnS quantum dots (QDs) using a scanning tunnelling microscope. Nearly monodisperse ultra-small QDs are achieved by a facile wet chemical route. The exact energy structures are evaluated by scanning tunnelling spectroscopy (STS) measurements at 300 mK for the individual nanoobjects starting from the main building block Au nanocrystals (NCs) to the final Au-ZnS QDs. The study divulges the evolution of the energy structure and the charge transport from the single metallic building block core to the core-shell metal-semiconductor QDs. Furthermore, we successfully determined the contributions related to the quantum-confinement-induced excitonic band structure of the ZnS nano-shell and the charging energy of the system by applying a semi-empirical approach considering a double barrier tunnel junction (DBTJ) arrangement. We detect strong conductance peaks in Au-ZnS QDs due to the overlapping of the energy structure of the Au nano-core and the discrete energy states of the semiconductor ZnS nano-shell. Our findings will help in understanding the electronic properties of metal-semiconductor QDs. The outcomes therefore have the potential to fabricate tailored metal-semiconductor QDs for single-electron devices.
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Affiliation(s)
- Tuhin Shuvra Basu
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany.
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Basu TS, Diesch S, Obergfell M, Demsar J, Scheer E. Energy scales and dynamics of electronic excitations in functionalized gold nanoparticles measured at the single particle level. Phys Chem Chem Phys 2019; 21:13446-13452. [DOI: 10.1039/c9cp02378j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The knowledge of the electronic structure in nanoparticles and their dynamics is a prerequisite to develop miniaturized single electron devices based on nanoparticles.
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Affiliation(s)
| | - Simon Diesch
- Department of Physics
- University of Konstanz
- 78457 Konstanz
- Germany
| | - Manuel Obergfell
- Institute of Physics
- Johannes Gutenberg-University Mainz
- 55128 Mainz
- Germany
| | - Jure Demsar
- Institute of Physics
- Johannes Gutenberg-University Mainz
- 55128 Mainz
- Germany
| | - Elke Scheer
- Department of Physics
- University of Konstanz
- 78457 Konstanz
- Germany
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