MeV Si ion beam modification effects on the thermoelectric generator from Er_0.1Fe_1.9SbGe_0.4 thin film

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• 作者：S. Budak ; S. Guner ; C. Muntele ; D. Ila
• 关键词：Ion bombardment ; Thermoelectric properties ; Multi-nanolayers ; Rutherford backscattering ; Figure of merit
• 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• 出版年：2009
• 出版时间：1 May 2009
• 年：2009
• 卷：267
• 期：8-9
• 页码：1592-1595
• 全文大小：318 K

文摘

Effective thermoelectric materials and devices have a low thermal conductivity and a high electrical conductivity. The performance of the thermoelectric materials and devices is shown by a dimensionless figure of merit, ZT. The purpose of this study is to improve the figure of merit of the single layer of Er_0.1Fe_1.9SbGe_0.4 thin film used as thermoelectric generators. We have deposited the monolayer of Er_0.1Fe_1.9SbGe_0.4 thin film on silicon and silica substrates with thickness of 302 nm using ion beam assisted deposition (IBAD). Rutherford backscattering spectrometry (RBS) was used to determine the total film thickness and stoichiometry. The MeV Si ion bombardments were performed on single layer of Er_0.1Fe_1.9SbGe_0.4 thin films at five different fluences between 5 × 10¹³−5 × 10¹⁵ ions/cm².The defect and disorder in the lattice caused by ion beam modification and the grain boundaries of these nanoscale clusters increase phonon scattering and increase the chance of annihilation of the phonon. The increase of the electron density of states in the miniband of the quantum dot structure formed by bombardment also increases the Seebeck coefficient and the electrical conductivity. We measured the thermoelectric efficiency of the fabricated device by measuring the cross plane thermal conductivity by the 3rd harmonic (3ω) method, the cross plane Seebeck coefficient, and the electrical conductivity using the Van Der Pauw method before and after the MeV ion bombardments.