Fabrication of photo-induced microstructure embedded inside ZnO crystal

In this paper, micromachining inside of direct and indirect semiconductor, such as zinc oxide crystal (ZnO) and single-crystalline silicon(c-Si) using femtosecond laser pulses is successfully demonstrated. In the case of ZnO, oxygen vacancy or interstitial zinc was three-dimensionally induced by the near-infrared femtosecond laser pulse irradiation. The threshold energy for oxygen defect formation increased with increasing in a pulse width. The mechanism of the pulsewidth dependence of the damage threshold inside ZnO could be interpreted in terms of the excitonic Mott transition to the electron-hole plasma which depends on the electron plasma density induced by the laser irradiation. We have also successfully micromachined inside c-Si using infrared ultrashort laser pulses (λ = 1.24 μm). Optical microscope observation under an infrared lamp illumination indicates low density material or scattering structure was formed in the vicinity of the focal spot.

[1]  Eric Mazur,et al.  Femtosecond laser micromachining in transparent materials , 2008 .

[2]  Jinhai Si,et al.  Periodic nanovoid structures via femtosecond laser irradiation. , 2005, Nano letters.

[3]  L. Glebov,et al.  Nonlinear photoionization and laser-induced damage in silicate glasses by infrared ultrashort laser pulses , 2009 .

[4]  J. Qiu,et al.  Self-formation of quasiperiodic void structure in CaF2 induced by femtosecond laser irradiation , 2007 .

[5]  Mengyan Shen,et al.  Visible and near-infrared responsivity of femtosecond-laser microstructured silicon photodiodes. , 2005, Optics letters.

[6]  Zhi‐zhan Xu,et al.  Optical absorption of two dimensional periodic microstructures on ZnO crystal fabricated by the interference of two femtosecond laser beams. , 2010, Optics express.

[7]  Y. Shimotsuma,et al.  Self-organized nanogratings in glass irradiated by ultrashort light pulses. , 2003, Physical review letters.

[8]  J. Rand,et al.  Silicon Nanowire Solar Cells , 2007 .

[9]  X. Qiu,et al.  Correlation between size-induced lattice variations and yellow emission shift in ZnO nanostructures , 2005 .

[10]  Andreas Tünnermann,et al.  Inscription of optical waveguides in crystalline silicon by mid-infrared femtosecond laser pulses. , 2005, Optics letters.

[11]  E. Mazur,et al.  Ultrafast-laser driven micro-explosions in transparent materials , 1997 .

[12]  Eric Mazur,et al.  Comparison of Structure and Properties of Femtosecond and Nanosecond Laser-Structured Silicon , 2004 .

[13]  R. Thangavel,et al.  Micro‐Raman scattering spectroscopy study of Li‐doped and undoped ZnO needle crystals , 2009 .

[14]  K. Miura,et al.  Writing waveguides in glass with a femtosecond laser. , 1996, Optics letters.

[15]  Vien Van,et al.  Femtosecond laser tuning of silicon microring resonators. , 2011, Optics letters.

[16]  Euan Hendry,et al.  Exciton and electron-hole plasma formation dynamics in ZnO , 2007 .

[17]  Naoya Matsumoto,et al.  Spherical aberration correction suitable for a wavefront controller. , 2009, Optics express.

[18]  A. Majumdar,et al.  Enhanced Thermoelectric Performance of Rough Silicon Nanowires. , 2008 .