Growth of high-quality GaN nanowires on p-Si (1 1 1) and their performance in solid state heterojunction solar cells

Saron, K.M.A.; Ibrahim, Mohammed; Taha, T.A.; Aljameel, A.I.; Alharbi, Abdullah G.; Alenad, Asma M.; Alshammari, Basheer A.; Almutairi, Ghzzai; Allam, Nageh K.

doi:10.1016/j.solener.2021.09.045

Cited by 8 publications

(7 citation statements)

References 49 publications

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“…The GaN E 2 (high) phonon mode can be used to measure the stress [ 18 , 37 , 38 ]. The GaN with free strain possesses an E 2 (high) phonon frequency of 567.5 cm −1 [ 18 ].…”

Section: Resultsmentioning

confidence: 99%

“…The GaN with free strain possesses an E 2 (high) phonon frequency of 567.5 cm −1 [ 18 ]. The Raman frequency difference of the GaN E 2 mode relative to the strain-free one Δω was used to calculate the layer stress using the formula: σ = Δω/K, where K = −4.3 cm −1 GPa −1 is the conversion factor of GaN Raman biaxial stress [ 37 , 38 ]. From the Lorentzian fitted E 2 mode peak values listed in Table 4 , S3 (NS38) and S6 (NS41) were found to exhibit tensile stress, while S2 (NS37) and S7 (NS48) were found to exhibit compressive stress.…”

Section: Resultsmentioning

confidence: 99%

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Optical, Structural, and Synchrotron X-ray Absorption Studies for GaN Thin Films Grown on Si by Molecular Beam Epitaxy

Feng,

Liu,

Xie

et al. 2024

Materials

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GaN on Si plays an important role in the integration and promotion of GaN-based wide-gap materials with Si-based integrated circuits (IC) technology. A series of GaN film materials were grown on Si (111) substrate using a unique plasma assistant molecular beam epitaxy (PA-MBE) technology and investigated using multiple characterization techniques of Nomarski microscopy (NM), high-resolution X-ray diffraction (HR-XRD), variable angular spectroscopic ellipsometry (VASE), Raman scattering, photoluminescence (PL), and synchrotron radiation (SR) near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. NM confirmed crack-free wurtzite (w-) GaN thin films in a large range of 180–1500 nm. XRD identified the w- single crystalline structure for these GaN films with the orientation along the c-axis in the normal growth direction. An optimized 700 °C growth temperature, plus other corresponding parameters, was obtained for the PA-MBE growth of GaN on Si, exhibiting strong PL emission, narrow/strong Raman phonon modes, XRD w-GaN peaks, and high crystalline perfection. VASE studies identified this set of MBE-grown GaN/Si as having very low Urbach energy of about 18 meV. UV (325 nm)-excited Raman spectra of GaN/Si samples exhibited the GaN E2(low) and E2(high) phonon modes clearly without Raman features from the Si substrate, overcoming the difficulties from visible (532 nm) Raman measurements with strong Si Raman features overwhelming the GaN signals. The combined UV excitation Raman–PL spectra revealed multiple LO phonons spread over the GaN fundamental band edge emission PL band due to the outgoing resonance effect. Calculation of the UV Raman spectra determined the carrier concentrations with excellent values. Angular-dependent NEXAFS on Ga K-edge revealed the significant anisotropy of the conduction band of w-GaN and identified the NEXAFS resonances corresponding to different final states in the hexagonal GaN films on Si. Comparative GaN material properties are investigated in depth.

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“…The GaN E 2 (high) phonon mode can be used to measure the stress [ 18 , 37 , 38 ]. The GaN with free strain possesses an E 2 (high) phonon frequency of 567.5 cm −1 [ 18 ].…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Optical, Structural, and Synchrotron X-ray Absorption Studies for GaN Thin Films Grown on Si by Molecular Beam Epitaxy

Feng,

Liu,

Xie

et al. 2024

Materials

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“…The apparent arrangement evolution depends on the NH 3 flow rate, indicating that the flow of NH 3 plays a crucial role in controlling the arrangement of GaN nanorods, similar to what has been reported previously. 30,31 The array modulation is related to the nucleation rate of GaN and the adhesion coefficient of Ga under different NH 3 flows. The higher NH 3 flow, the faster nucleation rate on the substrate surface, and the increase in the adhesion coefficient of Ga allow more Ga to adhere to the GaN surface, causing a change in the growth direction of GaN, which leads to the diversities in the arrangement of nanorods under different NH 3 flows.…”

Section: Array Regulation Of As-synthesized Gan Nanorodsmentioning

confidence: 99%

“…The higher NH 3 flow, the faster nucleation rate on the substrate surface, and the increase in the adhesion coefficient of Ga allow more Ga to adhere to the GaN surface, causing a change in the growth direction of GaN, which leads to the diversities in the arrangement of nanorods under different NH 3 flows. 30,31 3.6. Size Control of the As-Synthesized GaN Nanorod Arrays.…”

Section: Array Regulation Of As-synthesized Gan Nanorodsmentioning

confidence: 99%

Highly Controllable Epitaxial Growth of High-Density Nonpolar GaN Nanorod Arrays

Li,

Wang,

Chen

et al. 2024

Crystal Growth & Design

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The undesirable effects of the degraded device performance and shorter lifetime caused by the polarization electric field induced by polar GaN have contributed to an increasing interest in the fundamental research and promising applications of nonpolar GaN. Herein, we demonstrate a strategy to construct high-quality arrays of well-aligned nonpolar GaN nanorods on the Au-coated (100) γ-LiAlO 2 substrates by the chemical vapor deposition method. During the growth process, the Au particles that were originally at the tips of the nanorods were found to gradually disappear with time. The disappearance of Au particles solved the problem of catalyst contamination and also demonstrated an interesting growth mechanism: whereas the traditional vapor−liquid− solid dominated the initial growth stage, the Au catalyst began to migrate and detach under the relatively Ga-rich condition, and then the vapor−solid controlled the subsequent growth. The E 2 (high) phonon peak (567.7 cm −1 ) and the strong ultraviolet emission peak (362.0 nm) indicate that the nonpolar GaN nanorods are virtually strain-free and have a high crystallization quality. Additionally, the effects of NH 3 and the thickness of Au films on the growth of GaN nanorods were thoroughly investigated. The well-arranged nonpolar GaN nanorod arrays with excellent crystal quality will provide a referable nanomaterial choice for highperformance, high-efficiency nonpolar nanodevices.

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“…Slight differences in FWHM could be due to build up weak strain in SiIPAs. [45,46] To get more information stress/strain built up during the fabrication process, the Raman spectroscopy was also measured at room temperature, using the laser, having an excitation wavelength of 532 nm and the power of 0.05 mW. As shown in Figure 4b, optical phonon peak of bulk Si centered at 521.2 cm À1 of bulk silicon.…”

Section: Structural and Surface Characteristics Of Siipasmentioning

confidence: 99%

Lithography‐Free Method to Synthesize Quasiperiodic Silicon Inverted‐Pyramid Arrays: A Broadband Light Trapper for High‐Efficiency Thin Silicon Solar Cells

Kumar,

Rani,

Saini

et al. 2024

Solar RRL

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Thin silicon solar cells could be a low‐cost effective photo‐conversion device, if the device can efficiently absorb the solar spectrum. Here, a new lithography free technique has been developed for the fabrication of quasi‐periodic silicon inverted pyramids arrays (SiIPAs), which show a high light trapping phenomena in the UV‐VIS‐NIR (300 nm‐2000 nm). Fabricated SiIPA samples show a significant reduction of reflectance (3%) in the silicon absorption band (300 nm – 1000 nm). A unique additional absorption of 33 – 44% compared to the planar silicon, has been observed in the sub‐bandgap region of silicon (1100 – 2000 nm) for these samples. Photocurrent response measurement confirms the generation of additional electron‐hole pairs in the sub‐bandgap region of silicon for the SiIPA samples in comparison with planar sample. These results signify the effect of field confinement and the creation of optical resonance modes within these structures, qualitatively supported by numerical simulation. The estimated short circuit current density (JSC) using the experimental absorption spectrum of SiIP arrays is 55.46 mA/cm2, which is far higher than the Lambertian limit of ∽ 43 mA/cm2. The theoretical efficiency of the solar cell can be achieved up to 35.22%, which surpasses the Shockley‐Queisser limit of 33.7%.This article is protected by copyright. All rights reserved.

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Growth of high-quality GaN nanowires on p-Si (1 1 1) and their performance in solid state heterojunction solar cells

Cited by 8 publications

References 49 publications

Optical, Structural, and Synchrotron X-ray Absorption Studies for GaN Thin Films Grown on Si by Molecular Beam Epitaxy

Optical, Structural, and Synchrotron X-ray Absorption Studies for GaN Thin Films Grown on Si by Molecular Beam Epitaxy

Highly Controllable Epitaxial Growth of High-Density Nonpolar GaN Nanorod Arrays

Lithography‐Free Method to Synthesize Quasiperiodic Silicon Inverted‐Pyramid Arrays: A Broadband Light Trapper for High‐Efficiency Thin Silicon Solar Cells

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