Engineering Physics

Dr. R. R. LaPierre

Dr. R. R. LaPierre

Associate Professor
Department of Engineering Physics

McMaster University
1280 Main Street West, Hamilton
Ontario, Canada L8S 4L7

office: JHE/A324
email: lapierr@mcmaster.ca
voice: (905) 525-9140 x 27764
fax: (905) 527-8409

B.Sc. (Dalhousie), M. Eng. (McMaster), Ph.D. (McMaster), P. Eng

Research Interests

Nanostructures and Optoelectronics

Research Website: http://epic.mcmaster.ca/~lapierre/index.htm
Our research group focuses on controlling and manipulating the structure of semiconductor surfaces on the atomic scale for nanostructure, biomedical and optoelectronic device applications. The materials of primary interest in our work are III-V compound semiconductors used as sources, detectors, sensors, and photovoltaic (solar cell) devices. An molecular beam epitaxy (MBE) system is available for growth of semiconductor alloys containing In, Ga, As, P, Al, Sb and N. A wide range of deposition and processing techniques are under investigation to create nanoscale surface features. We have a large effort to develop third generation solar cells using nanowires. Various projects include:

Integration of organic or “soft” matter with compound semiconductor surfaces for biomedical device applications.
Understanding the fundamental semiconductor growth processes in molecular beam epitaxy.
Growth of semiconductor nanowires by the vapor-liquid-solid (VLS) growth technique.
Understanding and manipulating the interfacial properties of semiconductor heterostructures.

Selected Publications

2011:

49. R.R. LaPierre, Theoretical conversion efficiency of a two-junction nanowire on Si solar cell, J. Appl. Phys. (submitted, 2011).

48. Y.A. Pusep, A. Gold, M.C. Mamani, M. Godoy, Y.G. Gobato and R.R. LaPierre, Electron and hole scattering in short-period InGaAs/InP superlattices, Appl. Phys. Lett. (submitted, 2011).

47. A.C.E. Chia and R.R. LaPierre, Contact planarization of ensemble nanowires, Nanotechnology 22 (2011) 245304.

46. N. Tajik, Z. Peng, P. Kuyanov and R.R. LaPierre, Sulfur passivation and contact methods in GaAs nanowire solar cells, Nanotechnology 22 (2011) 225402.

45. R.R. LaPierre, Numerical model of current- voltage characteristics and efficiency of GaAs nanowire solar cells, J. Appl. Phys. 109 (2011) 034311.

44. P. K. Mohseni, G. Lawson, A. Adronov, and R. R. LaPierre, Hybrid GaAs Nanowire-carbon nanotube flexible photovoltaics , IEEE JSTQE (in press, 2011, DOI 10.1109/JSTQE.2010.2048097).

2010:

43. J. Baugh, J.S. Fung, J. Mracek, and R.R. LaPierre, Building a spin quantum bit register using semiconductor nanowires, Nanotechnology 21 (2010) 134018.

42. H. A. Budz, M. Ali, Y. Li, R. R. LaPierre, A hybrid aptamer-GaAs optical biosensor, J. Appl. Phys. (accepted for publication, 2010).

41. A. Fakhr, Y.M. Haddara and R.R. LaPierre, Dependence of InGaP nanowire morphology and structure on molecular beam epitaxy growth conditions, Nanotechnology 21 (2010) 165601.

40. Y.A.Pusep, P.K. Mohseni, R.R. LaPierre, A.K.Bakarov, and A.I.Toropov, A study of disorder effects in random (AlxGa1-xAs)n(AlyGa1-yAs)m superlattices embedded in a wide parabolic potential, Appl. Phys. Lett. 96 (2010) 113106.

39. P. K. Mohseni, G. Lawson, A. Adronov, and R. R. LaPierre, Hybrid GaAs Nanowire-carbon nanotube flexible photovoltaics , IEEE JSTQE (accepted for publication, 2010).

38. J. Caram, C. Sandoval, M. Tirado, D. Comedi, J. Czaban, and R. R.

LaPierre, Electrical characteristics of core-shell p-n GaAs nanowire structures with Te as the n-dopant, Nanotechnology 21 (2010) 134007.

37. E. De Jong, R R LaPierre, and J. Z. Wen, Detailed modeling of the epitaxial growth of GaAs nanowires, Nanotechnology 21 (2010) 045602.

36. M. Tirado, D. Comedi, and R. R. LaPierre, Impedance spectroscopy characterization of GaAs nanowire bundles grown by metal-catalyzed molecular beam epitaxy, J. Alloys and Compounds 495 (2010) 443-445.

35. D. Comedi, M. Tirado, C. Zapata, S. P. Heluani, M. Villafuerte, P.

Mohseni, and R.R. LaPierre, Randomly oriented ZnO nanowires grown on amorphous SiO2 by metal-catalyzed thermal evaporation, J. Alloys and Compounds 495 (2010) 439-442.

2009:

34. P.K. Mohseni, A.D.Rodrigues, J.C.Galzerani, Y.A. Pusep, and R.R.

LaPierre, Structural and optical analysis of GaAsP/GaP core-shell nanowires, J. Appl. Phys. 106 (2009) 124306.

33. H. Bi and R.R. LaPierre, GaAs nanowire/P3HT hybrid photovoltaic device, Nanotechnology 20 (2009) 465205.

32. M.C. Plante and R.R. LaPierre, Analytical description of the metal-assisted growth of III-V nanowires: axial and radial growths, J. Appl.

Phys. 105 (2009) 114304.

31. H.A. Budz, M.C. Biesinger and R.R. LaPierre, Passivation of GaAs by octadecanethiol self-assembled monolayers deposited from liquid and vapor phases, J. Vac. Sci. Technol. B 27 (2009) 637 .

30. S. C. Ghosh, P. Kruse, and R. R. LaPierre, Effect of GaAs (100) surface preparation on growth of nanowires, Nanotechnology 20 (2009) 115602.

29. J.A. Czaban, D.A. Thompson, and R.R. LaPierre, GaAs core-shell nanowires for photovoltaic applications, Nano Lett. 9 (2009) 148.

28. P.K. Mohseni and R.R. LaPierre, A growth interruption technique for stacking fault-free nanowire superlattices, Nanotechnology 20 (2009) 025610.

2008:

27. Y.A. Pusep, G.C. Gozzo, and R.R. LaPierre, Interface roughness in short-period InGaAs/InP superlattices, Appl. Phys. Lett. 93 (2008) 242104.

26. P.K. Mohseni, G. Lawson, C. Couteau, G. Weihs, A. Adronov and R.R.

LaPierre, Growth and characterization of GaAs nanowires on carbon nanotube composite films: towards flexible nano-devices, Nano Lett. 8 (2008) 4075.

25. M.C. Plante and R.R. LaPierre, Control of GaAs nanowire morphology and crystal structure, Nanotechnology 19 (2008) 495603.

24. H.A. Budz and R.R. LaPierre, Properties of octadecanethiol self-assembled monolayers deposited on GaAs from liquid and vapor phases, J.

Vac. Sci. Technol. A 26 (2008) 1425.

23. C. Chen, N. Braidy, C. Couteau, C. Fradin, G. Weihs, and R.R. LaPierre, Multiple quantum well AlGaAs nanowires, Nano Lett. 8 (2008) 495-499.

22. M.C. Plante and R.R. LaPierre, Au-assisted growth of GaAs nanowires by gas source molecular beam epitaxy: tapering, sidewall faceting and crystal structure, J. Cryst. Growth 310 (2008) 356-363.

2007:

21. P.K. Mohseni, C. Maunders, G.A. Botton, and R.R. LaPierre, GaP/GaAsP/GaP core-multishell nanowire heterostructures on (111) silicon, Nanotechnology

18 (2007) 445304.

20. C. Chen, S. Shehata, C. Fradin, C. Couteau, G. Weihs, and R.R.

LaPierre, Self-directed growth of AlGaAs core-shell nanowires for visible light applications, Nano Lett. 7 (2007) 2584.

19. D.M. Cornet and R.R. LaPierre, InGaAs/InP core-shell and axial heterostructure nanowires, Nanotechnology 18 (2007) 385305.

18. S.C. Ghosh, M.C. Biesinger, R.R. LaPierre, and P. Kruse, X-ray photoelectron spectroscopic study of the formation of catalytic Au nanoparticles on ultraviolet-ozone oxidized GaAs(100) substrates, J. Appl.

Phys. 101 (2007) 114322.

17. S.C. Ghosh, M.C. Biesinger, R.R. LaPierre, and P. Kruse, The role of proximity caps during the annealing of ultraviolet-ozone oxidized GaAs, J.

Appl. Phys. 101 (2007) 114321.

16. D.M. Cornet, V.G.M. Mazzetti, and R.R. LaPierre, Onset of stacking faults in InP grown by gas source molecular beam epitaxy, Appl. Phys. Lett.

90 (2007) 013116.

2006:

15. C. Chen, M.C. Plante, C. Fradin, and R.R. LaPierre, Layer-by-layer and step-flow growth mechanisms in GaAsP/GaP nanowire heterostructures, J.

Mater. Res. 21 (2006) 2801-2809.

14. M.C. Plante, J. Garrett, S.C. Ghosh, P. Kruse, H. Schriemer, T. Hall, and R. R. LaPierre, The formation of supported monodisperse Au nanoparticles by uv/ozone oxidation process, Appl. Surf. Sci. 253 (2006) 2348-2354.

13. D.M. Cornet, R.R. LaPierre, D. Comedi, and Y.A. Pusep, High resolution x-ray diffraction analysis of InGaAs/InP superlattices, J. Appl. Phys. 100

(2006) 043518.

12. Y.A. Pusep, A.G. Rodrigues, J.C. Galzerani, D. Comedi, and R.R.

LaPierre, Evidence of the miniband formation in InGaAs/InP superlattices, Brazilian J. Physics 36 (2006) 905.

11. Y.A. Pusep, A.G. Rodrigues, J.C. Galzerani, D.M. Cornet, D. Comedi, and R.R. LaPierre, Miniband effect on optical vibrations in short-period InGaAs/InP superlattices, Phys. Rev. B 73 (2006) 235344.

10. M.C. Plante and R.R. LaPierre, Growth mechanisms of GaAs nanowires by gas source molecular beam epitaxy, J. Cryst. Growth 286 (2006) 394-399.

2005:

9. R.R. LaPierre and M.C. Plante, Potential for novel magnetic structures by nanowire growth mechanisms, J. Magnetics 10 (2005) 108-112.

1995-1998:

8. R. R. LaPierre, D. A. Thompson and B. J. Robinson, Reduction of composition modulation of InGaAsP grown by atomic-hydrogen-assisted epitaxy producing improved double-heterostructure laser performance, Semicond. Sci. Technol. 13 (1998) 637.

7. R. R. LaPierre, D. A. Thompson and B. J. Robinson, Evaluation of plasma and thermal sources for atomic hydrogen-assisted epitaxy of InP, J. Vac. Sci. Technol. A 16 (1998) 590.

6. R. R. LaPierre, B. J. Robinson and D. A. Thompson, Growth mechanisms of III-V compounds by atomic hydrogen-assisted epitaxy, J. Cryst. Growth 191

(1998) 319.

5. R. R. LaPierre, B. J. Robinson and D. A. Thompson, The role of atomic hydrogen in argon plasma-assisted epitaxy of InGaAsP/InP, J. Vac. Sci. Technol. B 15 (1997) 1707.

4. R. R. LaPierre, B. J. Robinson and D. A. Thompson, Group V incorporation in InGaAsP grown on InP by gas source molecular beam epitaxy, J. Appl. Phys. 79 (1996) 3021.

3. R. R. LaPierre, T. Okada, B. J. Robinson, D. A. Thompson and G. C.

Weatherly, Lateral composition modulation in InGaAsP strained layers and quantum wells grown on (100) InP by gas source molecular beam epitaxy, J. Cryst. Growth 158 (1996) 6.

2. R. R. LaPierre, T. Okada, B. J. Robinson, D. A. Thompson and G. C.

Weatherly, Spinodal-like decomposition of InGaAsP/(100) InP grown by gas source molecular epitaxy, J. Cryst. Growth 155 (1995) 1.

1. R. R. LaPierre, B. J. Robinson and D. A. Thompson, Lateral composition modulation of InGaAsP deposited by gas source molecular beam epitaxy on (100) and (h11)-oriented InP substrates, Appl. Surf. Sci. 90 (1995) 437.