Exciton fine structure in undoped GaN epitaxial films

Volm, D.; Oettinger, K.; Streibl, T; Kovalev, D.; Ben‐Chorin, M.; Diener, J.; Meyer, B. K.; Majewski, J. A.; Eckey, L.; Hoffmann, A.; Amano, Hiroshi; Akasaki, Isamu; Hiramatsu, Kazumasa; Detchprohm, Theeradetch

doi:10.1103/physrevb.53.16543

Cited by 176 publications

(105 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Only a PL peak at 3.41 eV has been observed and tentatively attributed to strongly, localized excitons in structural defects, such as stacking faults or screw dislocations, 16 and a PL peak at 3.44 eV to neutral acceptor-bound excitons. 17,18 Since the GaN nanowires prepared in this study have not shown dislocations or stacking faults, similar to the previous report, 6,10 the PL peak at 3.437 eV is expected to result from strongly localized excitons, presumably neutral acceptor-bound excitons.…”

supporting

confidence: 59%

“…For I 2 , E bx of GaN nanowires is slightly smaller than that of undoped GaN epitaxial films, 6.2± 1.1 meV. 18 Meanwhile, from the I x fit, the E fx and the E bx for 3.437 eV peak are estimated to be 27.2 and 17.1 meV, respectively. The E bx for I x is larger than that ͑11 meV͒ of exciton bound to Mg and smaller than that ͑22 meV͒ of exciton bound to Zn.…”

Section: -mentioning

confidence: 99%

See 1 more Smart Citation

Photoluminescent characteristics of Ni-catalyzed GaN nanowires

Yoo

Hong

et al. 2006

Applied Physics Letters

View full text Add to dashboard Cite

The authors report on time-integrated and time-resolved photoluminescence ͑PL͒ of GaN nanowires grown by the Ni-catalyst-assisted vapor-liquid-solid method. From PL spectra of Ni-catalyzed GaN nanowires at 10 K, several PL peaks were observed at 3.472, 3.437, and 3.266 eV, respectively. PL peaks at 3.472 and 3.266 eV are attributed to neutral-donor-bound excitons and donor-acceptor pair, respectively. Furthermore, according to the results from temperature-dependent and time-resolved PL measurements, the origin of the PL peak at 3.437 eV is also discussed. © 2006 American Institute of Physics. ͓DOI: 10.1063/1.2243710͔One-dimensional GaN nanostructures including nanowires, nanorods, and nanotubes have recently attracted much attention because of their potential applications for optoelectronic devices in the nanoscale. 1,2 GaN nanowires have been synthesized by many different nanowire growth methods. [3][4][5][6] Among numerous nanowire synthesis methods, the metal catalyst-assisted vapor-liquid-solid ͑VLS͒ growth method has been widely employed because this technique offers easy and size-controllable growth of many semiconductor nanowires. However, since the metal catalysts used for nanowire growth may act as impurities in the nanomaterial and even a small amount of impurities in semiconductors can significantly change physical properties of the host materials, it is very important to characterize the impurities and defects in catalyst-assisted grown semiconductor nanomaterials. The effect of impurities and defects on the physical properties of host materials is also expected to increase with a reduction in the size of the materials. In addition, the unintentionally doped impurities in semiconductors make it difficult to accurately control their conductivities and optical properties. Nevertheless, the defect characterization of catalyst-assisted grown semiconductor nanowires has rarely been reported because of difficulties in elemental analysis and electrical device fabrications. 7 Meanwhile, optical characterization methods such as photoluminescence ͑PL͒ spectroscopy requiring no physical contacts are useful for defect characterization of the nanomaterials. 8 In particular, low temperature PL spectroscopy is a very sensitive and nondestructive tool for characterizing radiative defects in semiconductors. 9 Although a few papers on synthesis and PL spectra of GaN nanowires have previously been reported, 10 near-band-edge ͑NBE͒ PL peak positions from catalyst-assisted grown GaN nanowires have not been consistent with those of epitaxial thin films. 5,6 Furthermore, time-resolved PL ͑TRPL͒ spectroscopy enables the investigation of exciton lifetime, an important parameter related to defects in materials and device performance. Despite the importance of TRPL measurements, TRPL behavior in GaN nanowires has rarely been reported. 11 In this letter, we report on both time-integrated and time-resolved photoluminescent properties of GaN nanowires grown by the Nicatalyst-assisted VLS method.GaN nanowires were grown on a 2-nm-...

show abstract

supporting

confidence: 59%

Section: -mentioning

confidence: 99%

Photoluminescent characteristics of Ni-catalyzed GaN nanowires

Yoo

Hong

et al. 2006

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Thus, the heterostructure spectra demonstrate features absent for the GaN active layer. In particular, the free exciton transitions X A , X B , and X C , observed in all the PL spectra, are the same as those recorded for good quality GaN layers [24][25][26]. In other words, the spectrum of a heterostructure reflects fundamental optical properties of GaN.…”

Section: Resultsmentioning

confidence: 48%

Enhancement and Narrowing of Excitonic Lines in AlInN/GaN Heterostructures

et al. 2011

View full text Add to dashboard Cite

A study of the photoluminescence properties of AlInN/GaN in comparison with the spectrum of the GaN active layer of the same heterostructure is presented. The strong intensity lines of the observed photoluminescence spectra are associated with the formation, enhancement and narrowing of the excitonic lines in the flat band region of the active GaN layer. The phenomena in the presence of electric field near the heterostructure interface with the two-dimensional electron system are associated with nonlinear behaviour of recombination processes.

show abstract

“…The similar kinds of peaks have also been detected in chemically deposited nanosized CdSe thin films which were defined to be originating due to weak quantum confinement effect [28]. Further, considering the energy band gap of TiN as 3.23 eV -3.38 eV and the N deficiency in the composition, the higher energy peak was called to be attributed to the recombination of holes in the valence band with the electrons bound to the N vacancies in the shallow energy level beneath the conduction band, which can be called donor-bound excitons [29][30][31]. It has been visualized that the intensity of the PL spectra first decreases with the increase in nitriding time (for 60 min), and then increases for highest nitriding time.…”

Section: Research Articlementioning

confidence: 99%

Investigation of Titanium Nitride Thin Films Treated in Hot Cathode Arc Discharge Plasma System

Singh¹,

Dahiya²,

Malik³

et al. 2016

Appl. Sci. Lett.

View full text Add to dashboard Cite

Titanium thin films were grown using DC magnetron sputtering, and then treated in a hot cathode arc discharge plasma system for nitrding by keeping 80 % N2 and 20 % H2. In this plasma system, we can independently control the plasma and nitrding parameters. During our analyses, low intensity and larger FWHM of diffraction peaks clearly indicated that TiNx films are not fully crystalline and a large fraction of them is still amorphous. AFM measurement showed that there is a reduction in particle size (32.76 nm to 16.95 nm) as well as in surface roughness (35.6 nm to 31.8 nm) with an increase in nitriding time (60 min. to 120 min.). Photoluminescence measurement depicted the presence of strong peak at 3.24 eV and other weak peak at 3.37 eV for the sample nitrided for 120 min. The modifications in local electronic structure after nitriding are understood using XPS measurements at different elemental edges. TiNx films developed using DC magnetron sputtering and treated in plasma system may find applications in solar control panels and as a resistance to high temperature coatings.

show abstract

Exciton fine structure in undoped GaN epitaxial films

Cited by 176 publications

References 27 publications

Photoluminescent characteristics of Ni-catalyzed GaN nanowires

Photoluminescent characteristics of Ni-catalyzed GaN nanowires

Enhancement and Narrowing of Excitonic Lines in AlInN/GaN Heterostructures

Investigation of Titanium Nitride Thin Films Treated in Hot Cathode Arc Discharge Plasma System

Contact Info

Product

Resources

About