光子学报 ›› 2020, Vol. 49 ›› Issue (10): 1014002-1014002.doi: 10.3788/gzxb20204910.1014002

• 激光与激光光学 • 上一篇    下一篇

表面改性硅的超快激光脉冲制备及光电特性研究

杨洋, 李超, 赵纪红   

  1. 吉林大学 电子科学与工程学院 集成光电子国家重点实验室,长春 130012
  • 收稿日期:2020-04-28 接受日期:2020-06-30 出版日期:2020-10-25 发布日期:2020-10-13

Research on Fabrication and Optoelectronic Properties of Surface Modified Silicon by Ultrafast Laser Pulse

Yang YANG(), Chao LI, Ji-hong ZHAO()   

  1. State Key Laboratory of Integrated Optoelectronics,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China
  • Received:2020-04-28 Accepted:2020-06-30 Online:2020-10-25 Published:2020-10-13
  • About author:YANG Yang (1995-), male, B.S. degree candidate, mainly focuses on ultrafast laser fabrication of black silicon. Email:2262616446@qq.com|(Contact author): ZHAO Ji-hong (1984-), female, associate professor, Ph.D. degree, mainly focuses on ultrafast laser fabrication of black silicon. Email: zhaojihong@jlu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(61775077)

摘要:

为将单晶硅的吸收限拓展至近红外波段以满足光通讯之需求,利用纳秒激光脉冲辐照单晶硅表面制得了表面结构化的硅.研究了能量密度从0.39 J/cm2到24 J/cm2的激光脉冲辐照后结构化硅表面的形貌差异.测试并分析了不同能量密度的激光脉冲辐照后结构化硅的反射率、透过率和吸收率等光学性质.研究发现,相比于单晶硅衬底,所有结构化硅样品都表现出近红外吸收增强特性,对1 500 nm的近红外光的吸收率高达55%.进而对改性硅样品的红外吸收的热稳定性进行了研究.在473 ~1 073 K的温度范围内对改性硅样品进行退火,通过分析改性硅的反射率、透过率和吸收率随退火温度的变化规律,发现热退火处理会轻微降低改性硅样品的红外区吸收率,吸收率降低幅度低于10%.最后,通过分析脉冲激光改性硅的拉曼光谱,获得了改性硅的晶体结构信息.经过纳秒激光脉冲辐照后,硅表面处于无序化状态,形成非晶或多晶相,但是后热退火工艺可以有效改善结构化硅表面的晶体质量.

关键词: 结构化, 红外吸收, 热退火, 硅, 脉冲激光

Abstract:

In order to extend the absorption edge of crystalline silicon to the near infrared band to meet the requirement of optical communication,the textured silicon was obtained by irradiation of nanosecond laser pulses. The surface morphology of modified silicon under irradiation with different laser fluence from 0.39 J/cm2 to 24 J/cm2 was investigated. Then, the optical properties including reflectance, transmittance, and absorptance of silicon samples by nanosecond laser irradiation with different laser fluence were measured. The results show that the absorptance below the bandgap of silicon enhances for all the textured silicon samples and it is up to 55% for near infrared light of 1 500 nm. Next, the thermal stability of infrared absorption for the textured silicon samples was investigated. The thermal annealing process at temperatures of 473~1 073 K can slightly reduce the absorptance below the bandgap of silicon and the magnitude of reduction only varied within 10%. Moreover, the dependence of reflectance, transmittance, and absorptance of modified silicon on the annealing temperature was studied on. Lastly, the crystal structures of modified silicon were determined by Raman spectroscope. After irradiation of nanosecond laser pulses, the crystalline silicon surface is disordered and amorphous or polycrystalline phases are formed. However, the crystal quality of textured silicon can be improved by post-thermal annealing process.

Key words: Texturing, Infrared absorption, Thermal annealing, Silicon, Pulsed laser

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