Growth of dense ZnO films via MOVPE on GaN(0001) epilayers using a low/high-temperature sequence

Pierce, J. M.; Adekore, B. T.; Davis, R. F.; Stevie, F. A.

doi:10.1016/j.jcrysgro.2005.01.054

Cited by 20 publications

(23 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the past ten years, ZnO epilayer, ZnO nanorods, and various ZnO nanostructures have been grown by various techniques, including molecular beam epitaxy, 1-4 metal organic vapor phase epitaxy or metal organic chemical vapor deposition, [5][6][7][8][9][10] pulsed laser deposition, 11,12 vapor-liquid-solid ͑VLS͒ catalytic growth technique, [13][14][15] magnetron sputtering, 16 and chemical bath deposition ͑CBD͒. [17][18][19] A major advantage for ZnO nanostructures, e.g., nanowires and nanorods, is that they can be easily grown on various substrates and nonlattice materials including flexible polymers.…”

Section: Introductionmentioning

confidence: 99%

Surface recombination in ZnO nanorods grown by chemical bath deposition

Zhao¹,

Yang²,

Willander³

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

Vertically well-aligned ZnO nanorods on Si substrates were prepared by a two-step chemical bath deposition ͑CBD͒ method. The optical properties of the grown ZnO nanorods were investigated by time resolved photoluminescence spectroscopy. It was found that the effective decay time of the near bandgap recombination in the CBD grown ZnO nanorods strongly depends on the diameter of the ZnO nanorods. Typically, the decay curves obtained from these ZnO nanorods show a combination of two exponential decays. The experimental results show that the fast exponential decay is related to the surface recombination and the slow decay is related to the "bulk" decay. The measured decay time of the effective surface recombination decreases with decreasing diameter, while the bulk decay time remains unchanged. The results also show that an annealing treatment around 500°C significantly reduces the surface recombination rate. A simple carrier and exciton diffusion equation is also used to determine the surface recombination velocity, which results in a value between 1.5 and 4.5 nm/ps.

show abstract

Section: Introductionmentioning

confidence: 99%

Surface recombination in ZnO nanorods grown by chemical bath deposition

Zhao¹,

Yang²,

Willander³

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…2 %) with room temperature lattice parameters of a Z = 0.325 nm, c Z = 0.521 nm and a G = 0.319 nm, c G = 0.519 nm, one would expect that ZnO epitaxial thin films on GaN would produce superior properties. Epitaxial ZnO films have been grown on GaN substrates using different vapor-phase methods including metal-organic chemical vapor deposition (MOCVD), [18,19] metal-organic vapor-phase epitaxy, [20][21][22][23][24] pulsed laser deposition (PLD), [25][26][27] and molecular beam epitaxy (MBE). [28][29][30][31] Recently it was shown that lateral epitaxial overgrowth (LEO) of ZnO films on (111) spinel substrates could be accomplished in water at 90°C.…”

Section: Introductionmentioning

confidence: 99%

Growth of Heteroepitaxial ZnO Thin Films on GaN‐Buffered Al₂O₃ (0001) Substrates by Low‐Temperature Hydrothermal Synthesis at 90 °C

Kim

Andeen

et al. 2007

Adv Funct Materials

104

View full text Add to dashboard Cite

Heteroepitaxial ZnO films are successfully grown on nondoped GaN‐buffered Al2O3 (0001) substrates in water at 90 °C using a two‐step process. In the first step, a discontinuous ZnO thin film (ca. 200 nm in thickness) consisting of hexagonal ZnO crystallites is grown in a solution containing Zn(NO3)·6 H2O and NH4NO3 at ca. pH 7.5 for 24 h. In the second step, a dense and continuous ZnO film (ca. 2.5 μm) is grown on the first ZnO thin film in a solution containing Zn(NO3)·6 H2O and sodium citrate at ca. pH 10.9 for 8 h. Scanning electron microscopy, X‐ray diffraction, UV‐vis absorption spectroscopy, photoluminescence spectroscopy, and Hall‐effect measurement are used to investigate the structural, optical, and electrical properties of the ZnO films. X‐ray diffraction analysis shows that ZnO is a monocrystalline wurtzite structure with an epitaxial orientation relationship of (0001)[11$ \bar 2 $0]ZnO∥(0001)[11$ \bar 2 $0]GaN. Optical transmission spectroscopy of the two‐step grown ZnO film shows a bandgap energy of 3.26 eV at room temperature. A room‐temperature photoluminescence spectrum of the ZnO film reveals only a main peak at ca. 380 nm without any significant defect‐related deep‐level emissions. The electrical property of ZnO film showed n‐type behavior with a carrier concentration of 3.5 × 1018 cm–3 and a mobility of 10.3 cm2 V–1 s–1.

show abstract

“…The density of the pits is 7.5×10 5 -2.1×10 8 cm −2 which is less than the threading dislocation density of the GaN templates (≤6×10 8 cm −2 ). Pits have been observed by other groups for ZnO/GaN layers [15,16].…”

Section: Resultsmentioning

confidence: 56%

Properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates

Ive

Ben-Yaacov

Asamizu

et al. 2008

Phys. Status Solidi (c)

View full text Add to dashboard Cite

We studied the properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates. A two‐step growth procedure was used where a buffer layer was first deposited at 400 °C before the temperature was increased to 900 °C for the deposition of the epitaxial layer. Atomic force microscopy revealed locally straight steps on a 20 × 20 mm2 scan area. This indicates a step‐flow growth mode. The root‐mean‐square roughness was 2.6 nm. The surface exhibited hexagonal pits. The pit density was 7.5 × 105–2.1 × 108 cm–2. The full width at half maximums of w‐scans for the symmetric (0002) and the skew‐symmetric (20$ \bar 2 $1) reflections were 0.091° and 0.159°, respectively. The ZnO films were fully relaxed as revealed by reciprocal space maps for the (10$ \bar 1 $5) reflection. Gallium doped n‐type ZnO layers were deposited on (In,Ga)N light emitting diodes as transparent contacts. The electron concentration was 9.4 × 1019 cm–3 and the sheet resistance 45 W/sq. The resistivity and the mobility was 1.5 × 10–3 Wcm and 43 cm2/(Vs), respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Growth of dense ZnO films via MOVPE on GaN(0001) epilayers using a low/high-temperature sequence

Cited by 20 publications

References 31 publications

Surface recombination in ZnO nanorods grown by chemical bath deposition

Surface recombination in ZnO nanorods grown by chemical bath deposition

Growth of Heteroepitaxial ZnO Thin Films on GaN‐Buffered Al₂O₃ (0001) Substrates by Low‐Temperature Hydrothermal Synthesis at 90 °C

Properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates

Contact Info

Product

Resources

About

Growth of dense ZnO films via MOVPE on GaN(0001) epilayers using a low/high-temperature sequence

Cited by 20 publications

References 31 publications

Surface recombination in ZnO nanorods grown by chemical bath deposition

Surface recombination in ZnO nanorods grown by chemical bath deposition

Growth of Heteroepitaxial ZnO Thin Films on GaN‐Buffered Al2O3 (0001) Substrates by Low‐Temperature Hydrothermal Synthesis at 90 °C

Properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates

Contact Info

Product

Resources

About

Growth of Heteroepitaxial ZnO Thin Films on GaN‐Buffered Al₂O₃ (0001) Substrates by Low‐Temperature Hydrothermal Synthesis at 90 °C