Vertical transport in group III‐nitride heterostructures and application in AlN/GaN resonant tunneling diodes

Hermann, Martin; Monroy, E.; Helman, A.; Baur, Barbara; Albrecht, M.; Daudin, B.; Ambacher, O.; Stutzmann, M.; Eickhoff, Martin

doi:10.1002/pssc.200404771

Cited by 51 publications

(33 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We observe that the structural quality of GaN/AlN superlattices is particularly sensitive to the Ga/N ratio; the strain fluctuations induced by alternating GaN and AlN layers favor the formation of V-shaped pits, even in the Ga-bilayer growth window. 70,71 Strain relaxation by V-pit formation at terminated dislocations is commonly observed in GaN-related materials, particularly in the InGaN/GaN system, 72 where the majority of threading dislocations has no driving force to glide or is kinetically impeded to glide at the growth temperature. V pits are generally inverted hexagonal pyramids with ͕10-11͖ facets.…”

Section: Use Of a Ga Excessmentioning

confidence: 99%

GaN/AlN short-period superlattices for intersubband optoelectronics: A systematic study of their epitaxial growth, design, and performance

Kandaswamy¹,

Guillot²,

Bellet‐Amalric³

et al. 2008

Journal of Applied Physics

Self Cite

178

175

View full text Add to dashboard Cite

We have studied the effect of growth and design parameters on the performance of Si-doped GaN/AlN multiquantum-well ͑MQW͒ structures for intersubband optoelectronics in the near infrared. The samples under study display infrared absorption in the 1.3-1.9 m wavelength range, originating from the photoexcitation of electrons from the first to the second electronic level in the QWs. A commonly observed feature is the presence of multiple peaks in both intersubband absorption and interband emission spectra, which are attributed to monolayer thickness fluctuations in the quantum wells. These thickness fluctuations are induced by dislocations and eventually by cracks or metal accumulation during growth. The best optical performance is attained in samples synthesized with a moderate Ga excess during the growth of both the GaN QWs and the AlN barriers without growth interruptions. The optical properties are degraded at high growth temperatures ͑Ͼ720°C͒ due to the thermal activation of the AlN etching of GaN. From the point of view of strain, GaN/AlN MQWs evolve rapidly to an equilibrium average lattice parameter, which is independent of the substrate. As a result, we do not observe any significant effect of the underlayers on the optical performance of the MQW structure. The average lattice parameter is different from the expected value from elastic energy minimization, which points out the presence of periodic misfit dislocations in the structure. The structural quality of the samples is independent of Si doping up to 10 20 cm −3 . By contrast, the intersubband absorption spectrum broadens and blueshifts with doping as a result of electron-electron interactions. This behavior is independent of the Si doping location in the structure, either in the QWs or in the barriers. It is found that the magnitude of the intersubband absorption is not directly determined by the Si concentration in the wells. Instead, depending on the Al mole fraction of the cap layer, the internal electric field due to piezoelectric and spontaneous polarization can deplete or induce charge accumulation in the QWs. In fact, this polarization-induced doping can result in a significant and even dominant contribution to the infrared absorption in GaN/AlN MQW structures.

show abstract

Section: Use Of a Ga Excessmentioning

confidence: 99%

GaN/AlN short-period superlattices for intersubband optoelectronics: A systematic study of their epitaxial growth, design, and performance

Kandaswamy¹,

Guillot²,

Bellet‐Amalric³

et al. 2008

Journal of Applied Physics

Self Cite

178

175

View full text Add to dashboard Cite

show abstract

“…The strain fluctuations induced by Si doping and by the presence of the AlN barriers favor the formation of V-shaped pits, even in layers grown in the regime of 2 ML Ga-excess [18,28]. The suppression of these defects has been achieved by an enhancement of the Ga-flux so that growth is performed at the limit of Ga-accumulation.…”

Section: Quantum Well Structuresmentioning

confidence: 99%

Latest developments in GaN-based quantum devices for infrared optoelectronics

Monroy

Guillot

Leconte

et al. 2007

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

In this work, we summarize the latest progress in intersubband devices based on GaN/AlN nanostructures for operation in the near-infrared. We first discuss the growth and characterization of ultra-thin GaN/AlN quantum well and quantum dot superlattices by plasma-assisted molecular-beam epitaxy. Then, we present the performance of nitride-based infrared photodetectors and electro-optical modulators operating at 1.55 lm. Finally, we discuss the progress towards intersubband light emitters, including the first experimental observation of intersubband photoluminescence in nitride nanostructures.

show abstract

“…The quality of the GaN/AlN heterostructures was found to be particularly sensitive to the Ga/N ratio. The strain fluctuations induced by Si doping and by the presence of the AlN barriers favor the formation of V-shaped pits, even in layers grown in the regime of 2 ML Ga-excess [15,8]. The suppression of these defects has been achieved by an enhancement of the Ga-flux so that growth is performed at the limit of Ga-accumulation.…”

Section: Si-doped Gan/aln Multiple-quantum-well Structuresmentioning

confidence: 99%

MBE growth of nitride-based photovoltaic intersubband detectors

Monroy

Guillot

Leconte

et al. 2006

Superlattices and Microstructures

Self Cite

View full text Add to dashboard Cite

In this work, we present the plasma-assisted molecular-beam epitaxial growth of quantum well infrared photodetector (QWIP) structures, including the Si-doped GaN/AlN short-period superlattice of the active region, conductive AlGaN claddings and integration of the final device. The growth of Si-doped GaN/AlN multiple quantum well (QW) structures is optimized by controlling substrate temperature, metal excess and growth interruptions. Structural characterization confirms a reduction of the interface roughness to the monolayer scale. P-polarized intersubband absorption peaks covering the 1.33-1.91 µm wavelength range are measured on samples with QW thickness varying from 1 to 2.5 nm. The absorption exhibits Lorentzian shape with a line width around 100 meV in QWs doped 5 × 10 19 cm −3 . To prevent partial depletion of the QWs owing to the internal electric field, we have developed highly-conductive Si-doped AlGaN cladding layers using In as a surfactant during growth. Complete ISB photodetectors with 40 periods of 1 nm-thick Si-doped GaN QWs with 2 nm-thick AlN barriers have been grown on conductive AlGaN claddings, the Al mole fraction of the cladding matching the average Al content of the active region. Temperature-dependent photovoltage measurements reveal a narrow (∼90 meV) detection peak at 1.39 µm.

show abstract

Vertical transport in group III‐nitride heterostructures and application in AlN/GaN resonant tunneling diodes

Cited by 51 publications

References 47 publications

GaN/AlN short-period superlattices for intersubband optoelectronics: A systematic study of their epitaxial growth, design, and performance

GaN/AlN short-period superlattices for intersubband optoelectronics: A systematic study of their epitaxial growth, design, and performance

Latest developments in GaN-based quantum devices for infrared optoelectronics

MBE growth of nitride-based photovoltaic intersubband detectors

Contact Info

Product

Resources

About