讲座预告 | 南非自由州大学J.J. Terblans教授：Morphology-Controlled Multilayer Deposition for CZTS Solar Cells and Quantitative ToF-SIMS Analysis of Indium Segregation from Copper
报告题目：Morphology-Controlled Multilayer Deposition for CZTS Solar Cells and Quantitative ToF-SIMS Analysis of Indium Segregation from Copper
报 告 人：J.J. Terblans教授（南非自由州大学）
邀 请 人：夏志国 教授
报告时间：2026年6月11日（周四）上午11:00-12:00
报告地点：科技园1号楼501学术报告厅
报告摘要：
Diffusion and segregation phenomena in metallic thin films are critically important for multilayer materials used in electronic, photovoltaic, and surface-engineering applications. Accurate diffusion studies require well-defined multilayer structures with minimal premixing during deposition so that thermal annealing remains the dominant diffusion mechanism. This study investigates the influence of thin film morphology on multilayer diffusion behaviour and demonstrates the use of Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) for extracting quantitative segregation parameters. Multilayer Cu, Zn, and Sn thin films intended for Cu2ZnSnS4 (CZTS) solar cell absorber applications were sequentially deposited onto SiO2 substrates using Electron Beam Physical Vapor Deposition (EBPVD). Depth profiles obtained using Auger Electron Spectroscopy (AES) and TOF-SIMS revealed substantial intermixing in the as-deposited multilayers before annealing. To identify the origin of this premixing, individual Cu, Zn, and Sn thin films were deposited and analysed using Scanning Electron Microscopy (SEM). The SEM analysis showed that Zn and Sn films exhibited discontinuous island-like growth rather than smooth, homogeneous layers, contributing significantly to interfacial mixing. The influence of deposition rate on surface morphology was further investigated, and increased deposition rates were found to reduce island formation, particularly in Sn films, thereby improving layer continuity and suitability for diffusion studies.
In a complementary investigation, TOF-SIMS was employed to study the surface segregation behaviour of Indium in copper. Since TOF-SIMS quantification is strongly affected by matrix effects, calibration was performed using Cu/In co-evaporated thin films of varying composition prepared by EBPVD. Relative sensitivity factors for Indium in a copper matrix were determined to enable quantitative analysis. A polycrystalline Cu sample doped with 0.5 at% In was prepared by indium evaporation followed by annealing at 1173 K for 23 days. Surface segregation was induced by heating from 323 K to 873 K at 0.1 K s-1 while monitoring the surface indium concentration in situ using TOF-SIMS. Segregation profiles were analysed using modified Fick, Langmuir–McLean, and Darken models. The extracted diffusion and segregation parameters (as D₀ = 0.50 × 10-5 m²/s, Q = 176.0 kJ/mol, and ∆G = -64.4 kJ/mol) for Indium are in good agreement with corresponding Auger electron spectroscopy measurements. These results highlight the importance of controlling thin film morphology and demonstrate the effectiveness of calibrated TOF-SIMS analysis for quantitative diffusion and segregation studies in metallic thin film systems.
报告人简介：
Prof JJ Terblans is a Professor of Physics, Head of the Department of Physics, and Director of the Centre for Microscopy at the University of the Free State. His research focuses on solid-state physics, thin films, diffusion, segregation, and advanced materials characterization using techniques such as XPS, AES, SEM, TEM, and ToF-SIMS. Applications include nanomaterials, solar cells, sensors, catalysts, and industrial alloys. He has authored over 150 peer-reviewed publications. Prof Terblans has supervised numerous MSc and PhD students and maintains strong collaborations with industry partners, translating research into practical technologies. He continues to advance physics education, research excellence, and scientific innovation at UFS.
JJ Terblans 教授是自由州大学物理学教授、物理系主任及显微镜中心主任。他的研究主要集中在固态物理学、薄膜、扩散、偏析以及利用 XPS、AES、SEM、TEM 和ToF-SIMS 等技术对先进材料进行表征。其研究应用涵盖纳米材料、太阳能电池、传感器、催化剂及工业合金等领域。他已发表150余篇经同行评审的学术论文。Terblans教授指导了众多硕士和博士研究生，并与产业合作伙伴保持着紧密的合作关系，致力于将研究成果转化为实用技术。他持续推动自由州大学在物理教育、卓越研究及科学创新方面的进步。
