无机材料学报 ›› 2015, Vol. 30 ›› Issue (10): 1115-1120.DOI: 10.15541/jim20150197

• • 上一篇    

脉冲激光沉积中高能量密度激光密度对Cu2Se 热电薄膜成分与性能的影响

吕艳红1, 陈吉堃1, 2, DOBELI Max3, 李宇龙1, 史 迅1, 陈立东1   

  1. (1. 中国科学院 上海硅酸盐研究所, 中国科学院能量转换材料重点实验室, 上海200050; 2. 北京科技大学 材料科学与工程学院, 北京100083; 3. 瑞士苏黎世联邦理工大学 粒子物理中心, 苏黎世8093)
  • 收稿日期:2015-04-22 出版日期:2015-08-20 网络出版日期:2015-09-30
  • 作者简介:吕艳红. E-mail: lyh2012@student.sic.ac.cn

Congruent Growth of Cu2Se Thermoelectric Thin Films Enabled by Using High Ablation Fluence During Pulsed Laser Deposition

LV Yan-Hong1, CHEN Ji-Kun1, 2, DOBELI Max3, LI Yu-Long1, SHI Xun1, CHEN Li-Dong1   

  1. (1. CAS Key Laboratory of Materials for Energy Conversion, Shanghai institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China; 2. School of Materials Science and Engineering, University of Science and Fechnology Beijing, Beijing100083, China; 3. Ion Beam Physics, ETH Zurich, Zurich 8093, Switzerland)
  • Received:2015-04-22 Published:2015-08-20 Online:2015-09-30
  • About author:LV Yan-Hong(1987–), female, candidate of PhD. E-mail: lyh2012@student.sic.ac.cn
  • Supported by:
    National Basic Research Program of China(2013CB632501);National Natural Science Foundation of China(51472262)

摘要:

本工作提出了脉冲激光沉积法生长Cu2Se 热电材料薄膜中维持较高的激光切削能量密度对于实现薄膜与靶材成分等比例传输的重要性。使用较高的脉冲激光能量生长的Cu2Se薄膜具有纯的α-相, 并具有与靶材相近的化学组分。这主要是因为较高的激光能量可以更加有效地引起等离子体对激光-固体直接作用的屏蔽, 这可以使得靶材中的铜和硒元素的激光切削量更加接近靶材的化学计量比。由于硒具有较高的蒸汽压, 降低激光能量会加强激光与固体的直接作用, 从而更有效地切削硒元素, 导致所沉积薄膜中产生铜缺陷。进一步讨论了所使用的氩气背景气体压力对于所生长的Cu2Se薄膜热电性能的影响。当使用高激光能量低背景气体压力时, 所生长的薄膜具有最佳的热电性能。

关键词: Cu2Se 薄膜, 脉冲激光沉积, 热电, 激光能量

Abstract:

The importance of the laser ablation fluence in congruent growth of Cu2Se thermoelectric thin films during pulsed laser deposition was shown in this work. By using a larger laser ablation fluence, a more consistent composition between as-grown thin films and the target material has been realized in the pulsed laser deposition of Cu2Se films. This is associated with the enhanced plasma shielding effect, which weakens direct laser-solid interaction when increasing laser fluence. Reducing the ablation fluence can obviously increase the amount of the copper deficiencies, due to more effective laser ablation of Se (higher vapor pressure) than that of Cu when the laser direct lasser-solid interaction becomes more efficient. Apart from tuning the ablation fluence, thermoelectric performances of as-grown Cu2Se thin films are further optimized as a function of the used argon background gas pressures. The maximum thermoelectric performance of the Cu2Se thin film can be obtained when using the highest ablation fluence (~10 J/cm2) and a low argon background pressure(~10-1 Pa).

Key words: Cu2Se film, pulsed laser deposition, thermoelectric, ablation fluence

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