MOVPE growth of AlGaN/GaN superlattices on ZnO substrates for green emitter applications

Yu, Haiming; Wang, Shenjie; Li, Nola; Fenwick, William E.; Melton, Andrew; Klein, Benjamin; Ferguson, Ian T.

doi:10.1016/j.jcrysgro.2008.07.071

Cited by 18 publications

(11 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ZnO has been studied also for other applications including lasers [4], LEDs and varistors [5]. Single crystalline ZnO is of interest also as a substrate for the growth of GaN films [6]. Manuscript Recently, ZnO was tested as the alpha-ray detector [7]- [9].…”

Section: Introductionmentioning

confidence: 99%

Scintillation Properties of In Doped ZnO With Different In Concentrations

Yanagida

Fujimoto

Yoshikawa

et al. 2010

IEEE Trans. Nucl. Sci.

View full text Add to dashboard Cite

Using the liquid phase epitaxy (LPE) method we prepared the high crystalline quality In 3+ doped ZnO thin film scintillators with different Indium concentration of 26, 53, and 141 ppm. We evaluated their optical properties and radiation response, because there are few reports of radiation response of In-doped ZnO scintillator. In order to imitate the scintillator application, we measured the alpha-ray excited luminescence spectra. The emission bands peaking around 375 and 500 nm were observed, and with an increment of In 3+ , the intensity of both bands decreases. In the measurement of light yield, we optically coupled the sample with PMT R7600 by a silicone grease, and excitation was provided by 241 Am 5.5 MeV -rays. The samples showed of about 10% of the light yield of BGO scintillator which was used as a reference. Under the same excitation the scintillation decay was measured in all the samples as well.

show abstract

Section: Introductionmentioning

confidence: 99%

Scintillation Properties of In Doped ZnO With Different In Concentrations

Yanagida

Fujimoto

Yoshikawa

et al. 2010

IEEE Trans. Nucl. Sci.

View full text Add to dashboard Cite

show abstract

“…Satellite diffraction peaks from MQW samples confirm sharp interfaces between the QW and barrier. 41,42 Figure 2c shows the photoluminescence of regrown samples measured using a 193 nm ArF excimer laser, where similar emission peaks are found around 250 nm. Samples B and C show shoulder peaks attributed to slightly different Al compositions at the interface of the QW and barrier.…”

Section: ■ Materials Growth and Characterizationmentioning

confidence: 74%

Enhanced Pockels Effect in AlN Microring Resonator Modulators Based on AlGaN/AlN Multiple Quantum Wells

et al. 2022

View full text Add to dashboard Cite

AlN-on-sapphire is a promising integrated photonic platform for operation over a wide wavelength range from ultraviolet to infrared. However, this platform suffers from a weak second-order electro-optic effect, also known as the Pockels effect. Here, we demonstrate an enhanced Pockels effect by utilizing AlGaN/AlN multiple quantum wells (MQWs) regrown on the AlN layer. This enhancement is attributed to the large built-in polarization field in the MQWs, which results in a higher second-order susceptibility in the MQW layer due to the electric-field-induced second-order effect overlapping with the optical mode of the waveguiding device. To investigate this enhancement, we design and fabricate separate AlN microring resonator modulators (MRMs) with MQWs operating at two different wavelengths, 1550 and 780 nm. The resonance shift due to the Pockels effect is characterized by applied voltages and compared with the AlN MRM of similar dimensions but without MQWs. We observe enhanced resonance shift factors of 2.16 (at 1550 nm) and 1.56 (at 780 nm) for resonators with MQWs compared to those without MQWs. Through a modal overlap analysis between the MQW layers and the optical mode of the resonator, we extract the second-order susceptibility in the MQW regions, which is shown to be 20 (at 1550 nm) and 10 times (at 780 nm) higher compared to that of AlN. Our study paves a promising path for realizing III-nitride-integrated photonic modulators with a stronger Pockels effect by employing MQWs with an optimal overlap with the optical mode of the modulator.

show abstract

“…The energy band gap is a key factor in many fields of science, such as photovoltaics and optoelectronics. Ternary alloys can be obtained as random crystals or quasi-crystals short-period superlattices [2][3][4][5]. In the case of random crystals, in some systems there is a significant problem with obtaining materials in the full composition range without phase and concentration separation.…”

Section: Introductionmentioning

confidence: 99%

The Band-Gap Studies of Short-Period CdO/MgO Superlattices

et al. 2021

View full text Add to dashboard Cite

Trends in the behavior of band gaps in short-period superlattices (SLs) composed of CdO and MgO layers were analyzed experimentally and theoretically for several thicknesses of CdO sublayers. The optical properties of the SLs were investigated by means of transmittance measurements at room temperature in the wavelength range 200–700 nm. The direct band gap of {CdO/MgO} SLs were tuned from 2.6 to 6 eV by varying the thickness of CdO from 1 to 12 monolayers while maintaining the same MgO layer thickness of 4 monolayers. Obtained values of direct and indirect band gaps are higher than those theoretically calculated by an ab initio method, but follow the same trend. X-ray measurements confirmed the presence of a rock salt structure in the SLs. Two oriented structures (111 and 100) grown on c- and r-oriented sapphire substrates were obtained. The measured lattice parameters increase with CdO layer thickness, and the experimental data are in agreement with the calculated results. This new kind of SL structure may be suitable for use in visible, UV and deep UV optoelectronics, especially because the energy gap can be precisely controlled over a wide range by modulating the sublayer thickness in the superlattices.

show abstract

MOVPE growth of AlGaN/GaN superlattices on ZnO substrates for green emitter applications

Cited by 18 publications

References 16 publications

Scintillation Properties of In Doped ZnO With Different In Concentrations

Scintillation Properties of In Doped ZnO With Different In Concentrations

Enhanced Pockels Effect in AlN Microring Resonator Modulators Based on AlGaN/AlN Multiple Quantum Wells

The Band-Gap Studies of Short-Period CdO/MgO Superlattices

Contact Info

Product

Resources

About