Semipolar III Nitride Semiconductors: Crystal Growth, Device Fabrication, and Optical Anisotropy

MRS Bulletin ◽  
2009 ◽  
Vol 34 (5) ◽  
pp. 334-340 ◽  
Author(s):  
Mitsuru Funato ◽  
Yoichi Kawakami

AbstractSemipolar InGaN/GaN quantum wells (QWs) are quite attractive as visible light emitters. One of the reasons is that a better optical transition probability is expected because of weaker internal electric fields, compared to conventional polar QWs. In addition, in-plane optical polarization anisotropy, which is absent in conventional QWs, is another relevant property because it affects device design and also may provide a means for novel applications. We revealed that the in-plane optical anisotropy in semipolar QWs switched from one direction perpendicular to the [0001] crystal axis to the perpendicular direction as the In composition increases. This is a property unique to semipolar QWs and enables, for example, to make cavity mirrors of laser diodes by cleavage. In this article, we describe the concept of semipolar planes and fabrication of high-quality epitaxial films for semipolar QWs. Furthermore, we discuss device fabrication and optical polarization anisotropy.

2003 ◽  
Vol 798 ◽  
Author(s):  
Mitsuru Funato ◽  
Yoshinobu Kawaguchi ◽  
Shigeo Fujita

ABSTRACTThe dependence of the spontaneous emission lifetime of excitons in InGaN/GaN quantum disks (QDs) on the crystalline orientation is calculated. For 1-nm-thick QDs, it is found that the lifetime in the conventional c-oriented QDs is ten times as long as that in QDs tilted by 30° and 90°, and that the difference is pronounced by increasing the QDs thickness. This is totally due to the presence of the electric field in strained InGaN. Taking into account our preceding study, in which it was revealed that GaN on GaAs(114) was titled by 30°, we propose the use of GaAs(114) as a substrate for nitride light emitting devices to improve the optical transition probability.


2002 ◽  
Vol 13 (1) ◽  
pp. 24-35 ◽  
Author(s):  
S.M. Ryabchenko ◽  
Yu.G. Semenov ◽  
A.V. Komarov ◽  
T. Wojtowicz ◽  
G. Cywiński ◽  
...  

2002 ◽  
Vol 743 ◽  
Author(s):  
S. Kalliakos ◽  
P. Lefebvre ◽  
T. Taliercio ◽  
B. Gil

ABSTRACTWe have calculated the change of interband absorption spectra of a quantum well based on hexagonal group-III nitride semiconductors under photo-injection of high densities of electron-hole pairs. The screening of internal electric fields by such optical excitation is known to blue-shift and reinforce the ground-state optical transition. Due to the large values of densities of states and of internal fields, we predict novel properties that rather concern optical absorption via transitions between excited states. The absorption coefficient can be strongly enhanced by the optical excitation itself, in this particular spectral region, yielding the possibility for self-induced absorption properties. In other words, if sufficiently intense, an excitation laser can increase the absorption coefficient of the system at its own wavelength, thus providing a strong nonlinear optical response. Finally, we briefly discuss the potential application of these optical phenomena.


PIERS Online ◽  
2006 ◽  
Vol 2 (6) ◽  
pp. 562-566 ◽  
Author(s):  
Chun-Nan Chen ◽  
Kao-Feng Yarn ◽  
Win Jet Luo ◽  
Jih-Chen Chiang ◽  
Ikai Lo ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hwan-Seop Yeo ◽  
Kwanjae Lee ◽  
Young Chul Sim ◽  
Seoung-Hwan Park ◽  
Yong-Hoon Cho

Abstract Optical polarization is an indispensable component in photonic applications, the orthogonality of which extends the degree of freedom of information, and strongly polarized and highly efficient small-size emitters are essential for compact polarization-based devices. We propose a group III-nitride quantum wire for a highly-efficient, strongly-polarized emitter, the polarization anisotropy of which stems solely from its one-dimensionality. We fabricated a site-selective and size-controlled single quantum wire using the geometrical shape of a three-dimensional structure under a self-limited growth mechanism. We present a strong and robust optical polarization anisotropy at room temperature emerging from a group III-nitride single quantum wire. Based on polarization-resolved spectroscopy and strain-included 6-band k·p calculations, the strong anisotropy is mainly attributed to the anisotropic strain distribution caused by the one-dimensionality, and its robustness to temperature is associated with an asymmetric quantum confinement effect.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agata Bojarska-Cieślińska ◽  
Łucja Marona ◽  
Julita Smalc-Koziorowska ◽  
Szymon Grzanka ◽  
Jan Weyher ◽  
...  

AbstractIn this work we investigate the role of threading dislocations in nitride light emitters with different indium composition. We compare the properties of laser diodes grown on the low defect density GaN substrate with their counterparts grown on sapphire substrate in the same epitaxial process. All structures were produced by metalorganic vapour phase epitaxy and emit light in the range 383–477 nm. We observe that intensity of electroluminescence is strong in the whole spectral region for devices grown on GaN, but decreases rapidly for the devices on sapphire and emitting at wavelength shorter than 420 nm. We interpret this behaviour in terms of increasing importance of dislocation related nonradiative recombination for low indium content structures. Our studies show that edge dislocations are the main source of nonradiative recombination. We observe that long wavelength emitting structures are characterized by higher average light intensity in cathodoluminescence and better thermal stability. These findings indicate that diffusion path of carriers in these samples is shorter, limiting the amount of carriers reaching nonradiative recombination centers. According to TEM images only mixed dislocations open into the V-pits, usually above the multi quantum wells thus not influencing directly the emission.


2003 ◽  
Vol 126 (8) ◽  
pp. 467-471 ◽  
Author(s):  
K Kowalik ◽  
A Kudelski ◽  
J.A Gaj ◽  
T Wojtowicz ◽  
O Krebs ◽  
...  

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