Piezoelectric effects on the optical properties of GaN/AlxGa1−xN multiple quantum wells

Kim, H. S.; Lin, J. Y.; Jiang, H. X.; Chow, Weng W.; Botchkarev, A.; Morkoç̌, H.

doi:10.1063/1.122786

Cited by 106 publications

(74 citation statements)

References 15 publications

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“…It has been found that coherently strained Al 0.25 Ga .075 N can be grown up to ϳ300 A on GaN. 15 This indicates that strain relaxation should not cause a significant shift from these calculated Schottky heights. Doping density is found to have a significant effect on the effective Schottky height.…”

Section: Schottky Detectorsmentioning

confidence: 69%

Piezoelectric fields in nitride devices

Beach¹,

McGill²

1999

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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We have calculated the piezoelectric field and charge distribution for various III-nitride heterostructures. Our calculations include strain energy minimization and doping effects, and are presented to show the magnitude of piezoelectric effects in strained layers. We compare our calculated results to device results where available. These include the two-dimensional electron gas in heterojunction field effect transistors, Schottky diodes with strained layers for Schottky height engineering, and III-nitride single quantum wells. Calculations that included energy considerations resulted in good agreement between predicted and observed field and charge distributions for the heterojunction fields-effect transistors structure.

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Section: Schottky Detectorsmentioning

confidence: 69%

Piezoelectric fields in nitride devices

Beach¹,

McGill²

1999

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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“…Currently there are no measured data available on the interface roughness characteristics, to the best of our knowledge. In the absence of such data, the interface roughness correlation length L, and the rms height of interface roughness fluctuations ), 33 were taken as adjustable parameters. It was implicitly assumed that the interface roughness process could be adequately modeled in the Born approximation with the use of weak-perturbation theory, and that localization effects were negligible.…”

Section: D2 Monte Carlo Results For Hemtsmentioning

confidence: 99%

Monte Carlo Transport Studies of GaN High Electron Mobility Transistors (HEMTs) for Microwave Applications

Joshi¹

2004

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, ABSTRACT (Maximum 200 words)Calculations of the electronic mobility and drift velocity have been carried out for bulk GaN and AlGaN-GaN heterojunctions based on a Monte Carlo approach. Very good agreement with available experiments has been obtained, and the calculations yielded a set of best-fit transport parameters. The calculations were then extended for the large-signal nonlinear response characteristics of HEMTs with particular emphasis on inter-modulation distortion (IMD). The results demonstrated an optimal operating point for low IMD at reasonably large output power due to a minima in the IMD curve. An increase in dynamic range with temperature has been predicted, due to a relative suppression of interface roughness scattering. The results indicate increasing the mole fraction for the barrier layer, reducing the transit length, and introducing a thin AIN interfacial layer for suppressing real space transfer performance enhancements. Simulations were also carried out to probe possible enhancements in Gun effect oscillators. It has been shown that repetitive structures with serial segments to fashion a "muhiple domain" device could lead to significant improvements in output power over conventional, single-transit structure, and so such multiple GaN diodes merit serious experimental study. Monte Carlo studies of GaN HEMTs also probed the effects of scattering due to edge dislocations strains. For self-consistency, numerical solution of Schr'odinger, Poisson, and charge balance equations were used for the eigen-functions. Electron mobilities predictions around 1.711 x 10' cmVVs, are in close agreement with reported data. At the highest dislocation density of 10'° cm"^, mobility reductions of 16.8 percent and 8.6 percent are predicted for 77 K and 300 K, respectively. SUBJECT TERMS AbstractCalculations of the electronic mobility and drift velocity were carried out for bulk GaN and AlGaN-GaN heterojunctions based on a Monte Carlo approach. Very good agreement with available experiments was obtained, and the calculations yielded a set of best-fit transport parameters. The calculations were then extended for the large-signal nonlinear response characteristics of HEMTs with particular emphasis on intermodulation distortion (IMD). The results demonstrated an optimal operating point for low IMD at reasonably large output power due to a minima in the IMD curve. An increase in dynamic range with temperature has been predicted, due to a relative suppression of interface roughness scattering. The results indicate increasing the mole fraction for the barrier layer, reducing the transit lengt...

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“…From this the piezoelectric field strength can also be estimated. By comparing experimental and calculation results, a lower limit value of the piezoelectric field strength of about 560 kV/cm in GaN/Al 0.15 Ga 0.85 N MQWs as well as the electron and hole wave functions have been obtained for a 40 Å well MQW [8].…”

Section: Time-resolved Pl Spectramentioning

confidence: 99%

“…Recent work on the III-nitride alloy systems and MQWs has shown that localized excitons dominate the optical transitions in these systems at low temperatures [2][3][4]. And, it has been proposed and shown that piezoelectric fields due to lattice mismatch-induced strain in InGaN/GaN MQWs [5,6] and GaN/AlGaN QWs [6][7][8][9] are the primary reason for the large redshift of the photoluminescence (PL) emission peak. Indeed the piezoelectric field in strained layers has been used to modify the operating characteristics of devices fabricated from these materials [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Piezoelectric Effects in GaN/AlGaN Multiple Quantum Wells Probed by Picosecond Time-Resolved Photoluminescence

Kim

Lin

Jiang

et al. 1999

MRS Internet j. nitride semicond. res.

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Piezoelectric effects in GaN/AlGaN multiple quantum wells (MQWs) have been directly probed by picosecond time-resolved photoluminescence (PL) spectroscopy. The time-resolved PL spectra of the 40 Å well MQWs reveal that the PL transition peak position is in fact blueshifted at early delay times due to the collective effects of quantum confinement of carriers, piezoelectric field, and Coulomb screening. However, the spectral peak position shifts toward lower energies as the delay time increases and becomes redshifted at longer delay times. By comparing experimental and calculation results, we have obtained a low limit of the piezoelectric field strength to be about 560 kV/cm in the 40 Å well GaN/Al 0.15 Ga 0.85 N MQWs.

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Piezoelectric effects on the optical properties of GaN/AlxGa1−xN multiple quantum wells

Cited by 106 publications

References 15 publications

Piezoelectric fields in nitride devices

Piezoelectric fields in nitride devices

Monte Carlo Transport Studies of GaN High Electron Mobility Transistors (HEMTs) for Microwave Applications

Piezoelectric Effects in GaN/AlGaN Multiple Quantum Wells Probed by Picosecond Time-Resolved Photoluminescence

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