Projects / Programmes
EXPLOITATION OF LOCALIZED SURFACE PLASMON RESONANCE (LSPR) FOR DETECTION OF NANOPARTICLE TOPOLOGICAL SURFACE STATES (TSS) AND DEVELOPMENT OF NEW PHOTO-THERMAL TOPOLOGICAL INSULATOR NANOMATERIALS
| Code |
Science |
Field |
Subfield |
| 2.04.01 |
Engineering sciences and technologies |
Materials science and technology |
Inorganic nonmetallic materials |
| Code |
Science |
Field |
| 2.05 |
Engineering and Technology |
Materials engineering |
Bismuth selenide, Topological insulators, detection of topological surface states, localized surface plasmon resonance, UV-vis spectroscopy, photo-thermal effect, nanoparticles, single-crystals, hydrothermal method, synthesis of nanoparticles
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
36327 |
PhD Blaž Belec |
Materials science and technology |
Head |
2020 - 2022 |
0 |
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
1540 |
University of Nova Gorica |
Nova Gorica |
5920884000 |
0 |
Abstract
The proposed project will consist of two parts. In the first part, we will develop an analytical method which will enable easy and quick detection of topological surface states (TSS) directly on the topological insulator (TI) nanoparticles. This new method will eliminate the problem that limits the development and application of TI for years. Namely, the main problem in the case of the TI nanoparticles is lack of a suitable characterisation method for detection of the topological surface states (TSS), the features that define TI. The TSS can be destroyed by modifying either particle morphology or composition. This could happen due to various factors such as a sub-critical thickness, dopant concentration and surface contamination. Because of the limitations of already known conventional methods (angle-resolved photoemission spectroscopy – ARPES, transport properties, etc), there is no proven method that could detect TSS directly on the TI nanoparticles. Therefore, we cannot know if new nanoparticles are in its non-trivial or trivial insulating state. The proposed method will be therefore the first one, that will enable the detection of the TSS on the nanoparticles. As it was theoretically predicted and recently experimentally confirmed, a localized surface plasmon resonance (LSPR) can be considered as a proof of the existence of the TSS on the nanoparticles. Accordingly, the proposed method is based on observing the absorption peaks related to the LSPR modes. For the purpose of development of the proposed method, different Bi2-xAxSe3 (A =M3+) nanoparticles will be prepared. Since it is really important that their surface is clean, free of any adsorbents on its surface that can destroy TSS, the nanoparticles will be synthesized with our recently developed hydrothermal method. Such adsorbent-free nanoparticles will be used for the absorption measurements, where we will track the absorption peaks that relates to the LSPR modes. The absorbance will be measured using two different systems that use different optic geometry; a conventional UV-vis spectrophotometer and a microtiter plate reader (that eliminates the effect of the particles sedimentation). To validate the proposed method, the results will be compared with results obtained by conventional method for detection of TSS. As a reference method, angle-resolved photoemission spectroscopy (ARPES) will be used. This will be performed on single-crystals, grown by Bridgman method, with the same Bi2-xAxSe3 composition as the nanoparticle counterparts. Additionally, with the new developed method, we will be able also to determine the critical concentration of the dopants where TSS on the nanoparticles disappear. This is very important for the future development of new TI nanomaterials with improved surface electronic properties. The second part of the project is closely related to the observance of LSPR on the TI nanoparticles with the new method. Since the LSPR, due to the contribution of TSS, is a reason for the existence of the photothermal effect in the nanoparticles, the absorption measurements will enable us to predict which nanoparticles are potentially good photothermics. Therefore, in the second part we will measure the photothermal effect of the TI nanoparticles that, according to the absorbance measurements performed in the first part of the project, display LSPR. Since we will use different Bi2-xAxSe3 nanoparticles we will also be able to study the correlation between the TI nanoparticles composition, existence of the TSS and photo-thermal effect. This will enable development of new photothermal TI nanomaterials with controllable heating magnitude.
