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Investigating surface effects of GaN nanowires using confocal microscopy at below-band gap excitation

  • Lauren R. Richey-Simonsen (a1), Nicholas J. Borys (a2), Tevye R. Kuykendall (a3), P. James Schuck (a3), Shaul Aloni (a3) and Jordan M. Gerton (a1)...

We analyze the microscopic origins of subgap photoexcitations of individual gallium nitride (GaN) triangular cross-section nanowires (NWs), which are highly photoactive over a broadband spectral range. Using confocal hyperspectral photoluminescence (PL) microscopy, mid-gap states on the NWs were excited using subgap illumination, resulting in two distinct PL spectra corresponding to the polar (0001) and the semipolar $\left( {\bar 1101} \right)$ / $\left( {1\bar 101} \right)$ surfaces. Emission spectra are well represented by Gaussian functions with fitted centers of 1.99 ± 0.01 eV and 2.26 ± 0.01 eV, respectively. PL collected from the end facets exhibits interference fringes and a relative blue shift. Furthermore, the PL spectrum shifts strongly to the blue when the excitation intensity is increased. These observations are consistent with a qualitative model in which the PL results from excitation into a broad manifold of surface-associated states which are rapidly populated at a high excitation intensity and can couple to etalon modes via longitudinal photon emission.

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1. Reshchikov M.A. and Morkoc H.: Luminescence properties of defects of GaN. J. Appl. Phys. 97, 061310 (2005).
2. Philipps J.M., Müntze G.M., Hille P., Wallys J., Schörmann J., Teubert J., Hofmann D.M., and Eickhoff M.: Radical formation at the gallium nitride nanowire–electrolyte interface by photoactivated charge transfer. Nanotechnology 24(32), 325701 (2013).
3. Slimane A.B., Najar A., Elafandy R., San-Román-Alerigi Dá P., Anjum D., Ng T.K., and Ooi B.S.: On the phenomenon of large photoluminescence red shift in GaN nanoparticles. Nanoscale Res. Lett. 8(1), 342 (2013).
4. Goldberger J., He R., Zhang Y., Lee S., Yan H., Choi H-J., and Yang P.: Single-crystal gallium nitride nanotubes. Nature 422(6932), 599 (2003).
5. Kuykendall T., Pauzauskie P.J., Zhang Y., Goldberger J., Sirbuly D., Denlinger J., and Yang P.: Crystallographic alignment of high-density gallium nitride nanowire arrays. Nat. Mater. 3(8), 524 (2004).
6. Zhang J., Zhang L.D., Wang X.F., Liang C.H., Peng X.S., and Wang Y.W.: Fabrication and photoluminescence of ordered GaN nanowire arrays. J. Chem. Phys. 115(13), 5714 (2001).
7. Nguyen H.P.T., Zhang S., Cui K., Han X., Fathololoumi S., Couillard M., Botton G.A., and Mi Z.: p-Type modulation doped InGaN/GaN dot-in-a-wire white-light-emitting diodes monolithically grown on Si(111). Nano Lett. 11(5), 1919 (2011).
8. Schwartzberg A.M., Aloni S., Kuykendall T., Schuck P.J., and Urban J.J.: Optical cavity characterization in nanowires via self-generated broad-band emission. Opt. Express 19(9), 8903 (2011).
9. Sanders A., Blanchard P., Bertness K., Brubaker M., Dodson C., Harvey T., Herrero A., Rourke D., Schlager J., Sanford N., Chiaramonti A.N., Davydov A., Motayed A., and Tsvetkov D.: Homoepitaxial n-core:p-shell gallium nitride nanowires: HVPE overgrowth on MBE nanowires. Nanotechnology 22(46), 465703 (2011).
10. Kuykendall T., Aloni S., Jen-La Plante I., and Mokari T.: Growth of GaN@InGaN core–shell and Au–GaN hybrid nanostructures for energy applications. Int. J. Photoenergy 2009, 1 (2009).
11. Lähnemann J., Hauswald C., Wölz M., Jahn U., Hanke M., Geelhaar L., and Brandt O.: Localization and defects in axial (In,Ga)N/GaN nanowire heterostructures investigated by spatially resolved luminescence spectroscopy. J. Phys. D: Appl. Phys. 47(39), 394010 (2014).
12. Zhao S., Kibria M.G., Wang Q., Nguyen H.P.T., and Mi Z.: Growth of large-scale vertically aligned GaN nanowires and their heterostructures with high uniformity on SiO x by catalyst-free molecular beam epitaxy. Nanoscale 5(12), 5283 (2013).
13. Ohno T., Bai L., Hisatomi T., Maeda K., and Domen K.: Photocatalytic water splitting using modified GaN:ZnO solid solution under visible light: Long-time operation and regeneration of activity. J. Am. Chem. Soc. 134(19), 8254 (2012).
14. Sheetz R.M., Richter E., Andriotis A.N., Lisenkov S., Pendyala C., Sunkara M.K., and Menon M.: Visible-light absorption and large band-gap bowing of GaN1−x Sb x from first principles. Phys. Rev. B 84(7), 075304 (2011).
15. Akimov A.V., Muckerman J.T., and Prezhdo O.V.: Nonadiabatic dynamics of positive charge during photocatalystic water splitting on GaN(10–10) surface: Charge localization governs splitting efficiency. J. Am. Chem. Soc. 135(23), 8682 (2013).
16. Neaton J. and Zayak A.T.: Berkeley Lab, Molecular Foundry, Berkeley, CA. Personal Communication, 2015.
17. Abe R.: Recent progress on photocatalytic and photoelectrochemical water splitting under visible light irradiation. J. Photochem. Photobiol., C 11(4), 179 (2010).
18. Qiu J., Zeng G., Ha M-A., Ge M., Lin Y., Hettick M., Hou B., Alexandrova A.N., Javey A., and Cronin S.B.: Artificial photosynthesis on TiO2-passivated InP nanopillars. Nano Lett. 15(9), 6177 (2015).
19. Singh R., Molnar R.J., Ünlü M.S., and Moustakas T.D.: Intensity dependence of photoluminescence in GaN thin films. Appl. Phys. Lett. 64(3), 336 (1994).
20. Ponce F.A., Bour D.P., Götz W., and Wright P.J.: Spatial distribution of the luminescence in GaN thin films. Appl. Phys. Lett. 68(1), 57 (1996).
21. Li Q. and Wang G.T.: Spatial distribution of defect luminescence in GaN nanowires. Nano Lett. 10(5), 1554 (2010).
22. Upadhya P.C., Li Q., Wang G.T., Fischer A.J., Taylor A.J., and Prasankumar R.P.: The influence of defect states on non-equilibrium carrier dynamics in GaN nanowires. Semicond. Sci. Technol. 25(2), 024017 (2010).
23. Wang G.T., Talin A.A., Werder D.J., Creighton J.R., Lai E., Anderson R.J., and Arslan I.: Highly aligned, template-free growth and characterization of vertical GaN nanowires on sapphire by metal–organic chemical vapour deposition. Nanotechnology 17(23), 5773 (2006).
24. Reshchikov M.A., Morkoç H., Park S.S., and Lee K.Y.: Yellow and green luminescence in a freestanding GaN template. Appl. Phys. Lett. 78(20), 3041 (2001).
25. Toda Y., Matsubara T., Morita R., Yamashita M., Hoshino K., Someya T., and Arakawa Y.: Two-photon absorption and multiphoton-induced photoluminescence of bulk GaN excited below the middle of the band gap. Appl. Phys. Lett. 82(26), 4714 (2003).
26. Schuck P.J., Grober R.D., Roskowski A.M., Einfeldt S., and Davis R.F.: Cross-sectional imaging of pendeo-epitaxial GaN using continuous-wave two-photon microphotoluminescence. Appl. Phys. Lett. 81(11), 1984 (2002).
27. Chin A.H., Ahn T.S., Li H., Vaddiraji S., Bardeen C.J., Ning C., and Sunkara M.K.: Photoluminescence of GaN nanowires of different crystallographic orientations. Nano Lett. 7(3), 626 (2007).
28. Xu S., Hao Y., Zhang J., Jiang T., Yang L., Lu X., and Lin Z.: Yellow luminescence of polar and nonpolar GaN nanowires on r-plane sapphire by metal organic chemical vapor deposition. Nano Lett. 13(8), 3654 (2013).
29. Chen C-C., Yeh C-C., Chen C-H., Yu M-Y., Liu H-L., Wu J-J., Chen K-H., Chen L-C., Peng J-Y., and Chen Y-F.: Catalytic growth and characterization of gallium nitride nanowires. J. Am. Chem. Soc. 123(12), 2791 (2001).
30. Bao W., Melli M., Caselli N., Riboli F., Wiersma D.S., Staffaroni M., Choo H., Ogletree D.F., Aloni S., Bokor J., Cabrini S., Intonti F., Salmeron M.B., Yablonovitch E., Schuck P.J., and Weber-Bargioni A.: Mapping local charge recombination heterogeneity by multidimensional nanospectroscopic imaging. Science 338, 1317 (2012).
31. Kuykendall T.R., Altoe M.V.P., Ogletree D.F., and Aloni S.: Catalyst-directed crystallographic orientation control of GaN nanowire growth. Nano Lett. 14, 6767 (2014).
32. Van de Walle C.G. and Segev D.: Microscopic origins of surface states on nitride surfaces. J. Appl. Phys. 101(8), 081704 (2007).
33. Lakowicz J.R.: Principles of Fluorescence Spectroscopy, 2nd ed. (Kluwer Academic/Plenum Publishers, New York, NY, 1999); p. 58.
34. Novotny L. and Hecht B.: Principles of Nano-Optics (Cambridge University Press, Cambridge, England, 2006); pp. 33351.
35. Catchpole K.R. and Polman A.: Plasmonic solar cells. Opt. Express 16(26), 21793 (2008).
36. Pennanen A.M. and Toppari J.J.: Direct optical measurement of light coupling into planar waveguide by plasmonic nanoparticles. Opt. Express 21(S1), A23 (2013).
37. Reshchikov M.A., Demchenko D.O., Usikov A., Helava H., and Makarov Y.: Identification of point defects in HVPE-grown GaN by steady-state and time-resolved photoluminescence. In Gallium Nitride Materials and Devices X, Chyi J.-I., Fujioka H., and Morkoc H., eds. (Proceedings of SPIE 9363, Bellingham, Washington, 2015), p. 93630L.
38. Reshchikov M.A., Morkoç H., Park S.S., and Lee K.Y.: Two charge states of dominant acceptor in unintentionally doped GaN: Evidence from photoluminescence study. Appl. Phys. Lett. 81(26), 4970 (2002).
39. Lyons J.L., Alkauskas A., Janotti A., and Van de Walle C.G.: First-principles theory of acceptors in nitride semiconductors. Phys. Status Solidi B 252(5), 900 (2015).
40. Demchenko D.O., Diallo I.C., and Reshchikov M.A.: Yellow luminescence of gallium nitride generated by carbon defect complexes. Phys. Rev. Lett. 110(8), 087404 (2013).
41. Lyons J.L., Janotti A., and Van de Walle C.G.: Carbon impurities and the yellow luminescence in GaN. Appl. Phys. Lett. 97(15), 152108 (2010).
42. Kucheyev S.O., Toth M., Phillips M.R., Williams J.S., Jagadish C., and Li G.: Chemical origin of the yellow luminescence in GaN. J. Appl. Phys. 91(9), 5867 (2002).
43. Dhara S., Datta A., Wu C.T., Lan Z.H., Chen K.H., Wang Y.L., Chen Y.F., Hsu C.W., Chen L.C., Lin H.M., and Chen C.C.: Blueshift of yellow luminescence band in self-ion-implanted n-GaN nanowire. Appl. Phys. Lett. 84(18), 3486 (2004).
44. Reshchikov M.A., Visconti P., and Morkoc H.: Blue photoluminescence activated by surface states in GaN grown by molecular beam epitaxy. Appl. Phys. Lett. 78, 177 (2001).
45. Zhang X., Zhang X., Xu J., Shan X., Xu J., and Yu D.: Whispering gallery modes in single triangular ZnO nanorods. Opt. Lett. 34(16), 2533 (2009).
46. Kibria M.G., Zhao S., Chowdhury F.A., Wang Q., Nguyen H.P.T., Trudeau M.L., Guo H., and Mi Z.: Tuning the surface Fermi level on p-type gallium nitride nanowires for efficient overall water splitting. Nat. Commun. 5, 3825 (2014).
47. Tian W., Zhao C., Leng J., Cui R., and Jin S.: Visualizing carrier diffusion in individual single-crystal organolead halide perovskite nanowires and nanoplates. J. Am. Chem. Soc. 137(39), 12458 (2015).
48. Shafran E., Mangum B.D., and Gerton J.M.: Using the near-field coupling of a sharp tip to tune fluorescence-emission fluctuations during quantum-dot blinking. Phys. Rev. Lett. 107(3), 037403 (2011).
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