Glancing Angle Deposition

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Research Overview

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Glancing angle deposition (GLAD) is a physical vapor deposition process where the deposition flux is incident at a large angle with respect to the surface normal and the substrate is rotating. In GLAD, the substrate is rotated in the polar and azimuthal directions by two stepper motors programmed by a computer. During the deposition, the angle between the incoming vapor from the source and the surface normal to the substrate is set between 0 to 90 degree, and the substrate can rotate azimuthally. The main mechanisms that control the growth are the shadowing effect and surface diffusion. GLAD produces columnar structures through the effect of shadowing during film growth, while substrate rotation controls the shape of the columns. In this technique, there are three basic parameters that determine the morphology of the columns: the incident angle, the growth rate, and the substrate rotational speed. By changing the angle of incidence, the columns can be sculptured into a C-shape, S-shape, and zigzag shape, while by changing the ratio of the deposition rate to the rotational rate (which is defined as the pitch), the column morphology can be varied between matchstick, helical, and vertical columns. Since GLAD is a physical vapor deposition technique, it has many advantages in terms of controlling the growth of nanostructured thin films:

1. It can form a nano-column array naturally.

2. The porosity of the film can be controlled by changing the incident angle.

3. There is almost no restriction on materials since the growth process is a thermal evaporation.

4. The shape and in-plane alignment of columns can be easily modified.

5. It has the advantage of self-alignment due to the shadowing effect.

6. It can also generate three-dimensional nanostructures.

These advantages make the GLAD technique very promising for nanostructure fabrications.

Setup for GLAD

GLAD Animation

Publications

Y.-P. Zhao, D.-X. Ye, Pei-I Wang, G.-C. Wang, and T.-M. Lu, “Fabrication Si nano-columns and square springs on self-assembly colloid substrates,” International Journal of Nanoscience 1, 87 (2002).
Y.-P. Zhao, D.-X. Ye, G.-C. Wang, and T.-M. Lu, “Novel nano-column and nano-flower arrays by glancing angle deposition,” Nano Letters 2, 351–354 (2002).
D.-X. Ye, Y.-P. Zhao, G.-R. Yang, Y.-G. Zhao, G.-C. Wang, and T.-M. Lu, “Manipulating the column tilt angles of nanocolumnar films by glancing angle deposition,” Nanotechnology 13, 615–618 (2002).
F. Tang, D.-L. Liu, D.-X. Ye, Y.-P. Zhao, T.-M. Lu, G.-C. Wang, and A. Vijayaraghavan, “Magnetic properties of Co nanocolumns fabricated by oblique-angle deposition,” J. Appl. Phys. 93, 4194–4200 (2003).
T. Karabacak, J. P. Singh, Y.-P. Zhao, G.-C. Wang, and T.-M. Lu, “Scaling during shadowing growth of isolated nanocolumn,” Phys. Rev. B 68, 125408 (2003).
J.-G. Fan and Y.-P. Zhao, “Direct deposition of aligned nanorod array onto cylindrical objects,” J. Vac. Sci. Technol. B 23, 947–953 (2005).
Y.-P. Zhao, S.-H. Li, S. B. Chaney, S. Shanmukh, J.-G. Fan, R. A. Dluhy, and W. Kisaalita, “Designing nanostructures for sensor applications,” J. Electric Mater. 35, 846–851 (2006).
Y. He, J. Fu, Y. Zhang, Y. Zhao, L. Zhang, A. Xia, and J. Cai, "Multilayered Si/Ni nanosprings and their magnetic properties," Small 3, 153–160 (2007).
W. Smith, Z.-Y. Zhang, and Y.-P. Zhao, “Structural and optical characterization of WO3 nanorods/films prepared by oblique angle deposition,” J. Vac. Sci. Technol. B 25, 1875–1881 (2007).
Y.-P. He, Y.-P. Zhao, and J.-S. Wu, “The effect of Ti doping on the growth of Mg nanostructures by oblique angle co-deposition,” Appl. Phys. Lett. 92, 063107 (2008).
J.-X. Fu, Y.-P. He, and Y.-P. Zhao, “Fabrication of heteronanorod structures by dynamic shadowing growth,” IEEE Sensors 8, 989–997 (2008).
J.-X. Fu, B. Park, G. Siragusa, L. Jones, R. A. Tripp,Y.-P. Zhao, and Y.-J. Cho, “Au/Si hetero-nanorod-based biosensor for Salmonella detection,” Nanotechnology 19, 155502 (2008).
Y.-P. He, Z.-Y. Zhang, C. Hoffmann, and Y.-P. Zhao, “Embedding Ag nanoparticles into MgF2 nanorod arrays,” Advanced Functional Materials 18, 1676–1684 (2008).
R. Blackwell and Y.-P. Zhao, “Metal nanoparticle embedded porous thin film prepared by oblique angle co-evaporation,” J. Vac. Sci. Technol. B 26, 1344–1349 (2008).
W. Smith and Y.-P. Zhao, “Enhanced photocatalytic activity by aligned WO3/TiO2 two-layer nanorod array,” J. Phys. Chem. C 112, 19635–19641 (2008).
W. Smith and Y.-P. Zhao, “Superior photocatalytic performance by vertically aligned core-shell TiO2/WO3 nanorod arrays,” Catalysis Communications 10, 1117–1121 (2009).
Y.-P. He and Y.-P. Zhao, “Mg nanostructures tailored by glancing angle deposition,” Crystal Growth & Design 10, 440–448 (2010).
Yuping He, Jianguo Fan, and Yiping Zhao, “Engineering a well-aligned composition-graded CuSi nanorod array by an oblique angle co-deposition technique,” Crystal Growth & Design 10, 4954–4958 (2010).
Y.-P. He and Y.-P. Zhao, "Advanced multi-component nanostructures designed by dynamic shadowing growth," Nanoscale 3, 2361-2375 (2011).
George Larsen, Robert Carl Fitzmorris, Jin Z. Zhang, and Yiping Zhao, "Structural, optical, and photocatalytic properties of Cr:TiO2 nanorod array fabricated by oblique angle co-deposition," J. Phys. Chem. C 115, 16892–16903 (2011).
Y.-P. Zhao, Y.-P. He, and C. Brown, "Composition dependent nanocolumn tilting angle during the oblique angle co-deposition," Appl. Phys. Lett. 100, 033106 (2012).
Yuping He, Bo Yang, Kaikun Yang,Cameron Brown,Ramaraja Ramasamy,Howard Wang,Cynthia Lundgren,and Yiping Zhao, "Designing Si-based nanowall arrays by dynamic shadowing growth to tailor the performance of Li-ion battery anodes," Journal of Materials Chemistry 22, 8294–8303 (2012).
Qin Zhou, Xian Zhang, Yu Huang, Zhengcao Li,Yiping Zhao, and Zhengjun Zhang, "Enhanced SERS performance by folding Silver nanorods," Appl. Phys. Lett. 100, 113101 (2012).
Hao Zhu, Wei Cao, George K. Larsen, Ryan Toole, and Yiping Zhao, “Tilting angle of nanocolumnar films fabricated by oblique angle deposition,”Journal of Vacuum Science and Technology B 30, 030606 (2012).
George K. Larsen, Bob C. Fitzmorris, Claudia Longo, Jin Z. Zhang, and Yiping Zhao, "Nanostructured homogenous CdSe/TiO2 composite visible light photoanodes fabricated by oblique angle codeposition," Journal of Materials Chemistry 22, 14205–14218 (2012).
Yuping He, Cameron Brown, Cynthia A. Lundgren, and Yiping Zhao, "The growth of CuSi composite nanorod arrays by oblique angle co-deposition, and their structural, electrical, and optical properties," Nanotechnology 23, 365703 (2012).
R. C. Jayasinghe, A. G. U. Perera, H. Zhu, and Y. Zhao, "Optical properties of nanostructured TiO2 thin films and their application as antireflection coatings on infrared detectors," Opt. Lett. 37, 4302–4304 (2012).
Pradip Basnet, George K. Larsen, Ravirajsinh P. Jadeja, Yen-Con Hung, and Yiping Zhao, "α-Fe2O3 nanocolumns and nanorods fabricated by electron beam evaporation for visible light photocatalytic and antimicrobial applications," ACS App. Mater. Interfaces 5, 2085–2095(2013).
Yizhuo He, Pradip Basnet, Simona Murph, and Yiping Zhao, "Ag nanoparticle embedded TiO2 composite nanorod arrays fabricated by oblique angle deposition: toward plasmonic photocatalysis," ACS Applied Materials & Interfaces 5, 11818–11827 (2013).
George K. Larsen, Yizhuo He, Jin Wang, and Yiping Zhao, "Scalable fabrication of composite Ti/Ag plasmonic helices: controlling morphology and optical activity by tailoring material properties," Adv. Opt. Mat. 2, 245–249 (2014).
Kun Yao, Ryan Toole, Pradip Basnet, and Yiping Zhao, “Highly sensitive double-layered nanorod array gas sensors prepared by oblique angle deposition,” Appl. Phys. Lett. 104, 073110 (2014).
Yizhuo He, George Larsen, Whitney Ingram, and Yiping Zhao, "Tunable three-dimensional helically stacked plasmonic layers on nanosphere monolayers," Nano Letters 14, 1976–1981 (2014).
Yizhuo He, George Larsen, Xibo Li, Whitney Ingram, Funing Chen, and Yiping Zhao, "Nanoscale conical Swiss roll with broadband visible and near-IR circular dichroism," Advanced Optical Materials 3, 342–346 (2015).
Pradip Basnet and Yiping Zhao, "Tuning the CuxO nanorod composition for efficient visible light induced photocatalysis," Catalysis Science & Technology 6, 2228 - 2238 (2016).
Kun Yao, Pradip Basnet, Henry Sessions, Simona E. Hunyadi Murph, and Yiping Zhao, "Fe2O3-TiO2 core-shell nanorod arrays for visible light photocatalytic applications," Catalysis Today 270, 51 - 58 (2016).
Steven Larson and Yiping Zhao, "Tuning the Composition of BixWyO nanorods towards zero bias PEC water splitting," Nanotechnology 27, 255401 (2016).
Steven Larson, Weijie Huang, and Yiping Zhao, "Combinatorial fabrication of composite nanorods using oblique angle co-deposition," Nanotechnology 27, 365304 (2016).
Caiqin Han, Dexian Ye, Yiping Zhao. and Junxue Fu, "Physical vapor deposition of Ag nanoparticles through shadowing and re-emission effects," Journal of Vacuum Science and Technology B 36, 051802 (2018).
Yanfeng Wang, Zhengjun Zhang, and Yiping Zhao, "The IR plasmonic properties of sub-wavelength ITO rod arrays predicted by anisotropic effective medium theory," Nanotechnology 31, 075203 (2020).
Weijie Huang, Xibo Li, Bin Ai, and Yiping Zhao, “Facile fabrication of composite Ag/Fe3O4 and porous Fe3O4 nanorods based on oblique angle co-deposition,” J. Phys. Chem. C 125, 11750–11755 (2021).

Wetting of Nanostructures

J. G. Fan, X. J. Tang, and Y.-P. Zhao, “Water contact angles of vertically aligned Si nanorod arrays,” Nanotechnology 15, 501–504 (2004).
J.-G. Fan, D. Dyer, G.-G. Zhang, and Y.-P. Zhao, “Nano-carpet effect: pattern formation during the wetting of vertically aligned nanorod array,” Nano Letters 4, 2133–2138 (2004).
J.-G. Fan and Y.-P. Zhao, “Characterization of watermarks formed in nano-carpet effect,” Langmuir 22, 3662–3671 (2006).
Y.-P. Zhao and J.-G. Fan, “Clusters of bundled nanorods in nanocarpet effect,” Appl. Phys. Lett., 88, 103123 (2006).
J.-G. Fan and Y.-P. Zhao, “Spreading of a water droplet on a vertically aligned Si nanorod array surface,” Appl. Phys. Lett. 90, 013102 (2007).
J.-G. Fan, J.-X. Fu, A. Collins, and Y-P Zhao, “The effect of the shape of nanorod arrays on the nanocarpet effect,” Nanotechnology 19, 045713 (2008).
J.-G. Fan and Y.-P. Zhao, “Freezing a water droplet on an aligned Si nanorod array substrate,” Nanotechnology 19, 155707 (2008).
J. G. Fan and Y.-P. Zhao, "Nanocarpet effect induced superhydrophobicity," Langmuire 26, 8245–8250 (2010).
Aisha Leh, Hartmann N'guessan, Jianguo Fan, Prashant Badahur, Rafael Tadmor, Yiping Zhao, "On the role of the three-phase contact line in surface deformation," Langmuir 28, 5795–5801 (2012).