Professor of Electrical Engineering

Ph. D.



Kato, Hyogo 673-1494, Japan

E-mail: koyama

(Please add our domain name: @hyogo-u.ac.jp)

Major Research Projects

-- Fabrication of anisotropic porous silicon layers by anodization under polarized illumination

-- Establilshment of simple and safe fabrication methods of porous silicon layers for educational purposes

-- Evaluation of excitation energy transfer by means of photoluminescence polarization memory in systems of porous silicon/laser dye or porous anodic alumina/laser dye nanocomposites

-- Development of simple and effective teaching tools on measurement and control, optical communication, etc.









Anisotropic porous silicon nanostructures

Porous silicon layers made by electrochemical etching under polarized illumination show anisotropic luminescence

See the original paper for details



Recent Publications


1) H. Koyama, gDifferent behavior of photoluminescence anisotropy in porous silicon layers made by polarized-light-assisted electrochemical etchingh, Appl. Phys. Lett. vol.80, no.6, pp.965-967 (2002).

2) H. Koyama, gAnisotropic photoluminescence from porous silicon layers made under polarized illumination: Origin of contradictory experimental observationsh, J. Appl. Phys. vol.93, no.5, pp.2410-2413 (2003).

3) H. Koyama, gPolarization properties of the visible photoluminescence from porous siliconh (Invited review paper), Recent Research Developments in Applied Physics vol.6 (Transworld Research Network, Kerala, India, 2003) pp.373-389.

4) H. Koyama, gIn-plane refractive index anisotropy in porous silicon layers induced by polarized illumination during electrochemical etchingh, J. Appl. Phys. vol.96, no.7, pp.3716-3720 (2004).

5) H. Koyama and K. Takemura, gFabrication of luminescent porous silicon layers using extremely dilute HF solutionsh, in Nanoscale Devices, Materials, and Biological Systems: Fundamental and Applications, M, Cahay, M.Urquidi-Macdonald, S. Bandyopadhyay, P. Guo, H. Hasegawa, N. Koshida, J. P. Leburton, D. J. Lockwood, S. Seal, and A. Stella (eds.), The Electrochemical Society (2004) p.289.

6) H. Koyama, gStrong photoluminescence anisotropy in porous silicon layers prepared by polarized-light assisted anodizationh, to be published in Solid State Commun. Solid State Commun. vol.138, no.12, pp.567-570 (2006).

7) H. Koyama, gPhotoluminescence properties of porous silicon layers prepared by electrochemical etching in extremely dilute HF solutionsh, J. Appl. Electrochem. vol.36, no.9, pp.999-1003 (2006).

8) A. Chouket, H. Elhouichet, M. Oueslati, H. Koyama, B. Gelloz, and N. Koshida, gEnergy transfer in porous-silicon/laser-dye composite evidenced by polarization memory of photoluminescenceh, Appl. Phys. Lett. vol.91, 211902 (2007)


9) B. Gelloz, H. Koyama, and N. Koshida, gPolarization memory of blue and red luminescence from nanocrystalline porous silicon treated by high-pressure water vapor annealingh, Thin Solid Films vol.517, pp.376-379 (2008).

10) A. Chouket, B. Gelloz, H. Koyama, H. Elhouichet, M. Oueslati, and N. Koshida, gEffect of high-pressure water-vapor annealing on energy transfer ini dye-impregnated porous siliconh, J. Lumin. vol.129, pp.1332-1335 (2009).

11) A. Chouket, H. Elhouichet, H. Koyama, B. Gelloz, M. Oueslati, and N. Koshida, gMultiple energy transfer in porous silicon/Rh6G/RhB nanocomposite evidenced by photoluminescence and its polarization memoryh, Thin Solid Films vol.518, pp.S212-S216 (2010).

12) B. Gelloz, N. Harima, H. Koyama, H. Elhouichet, and N. Koshida, gEnergy transfer from phosphorescent blue-emitting oxidized porous silicon to rhodamine 110h, Appl. Phys. Lett. vol.97, 171107 (2010).

13) H. Elhouichet, N. Harima, H. Koyama, and N.V. Gaponenko, gEnergy transfer in porous anodic alumina/rhodamine 110 nanocompositesh, J. Lumin. vol.132, pp.2232-2234 (2012).

List of other publications

Japanese page