Sino Nitride Semiconductor Co | Date: 2012-05-22
The present application discloses a composite substrate used for GaN growth, comprising a thermally and electrically conductive layer (
Sino Nitride Semiconductor Co. | Date: 2012-07-23
The present application discloses a composite substrate with a protective layer for preventing metal from diffusing, comprising: a thermally and electrically conductive layer (
Sino Nitride Semiconductor Co. | Date: 2012-05-22
A method for preparing a composite substrate for GaN growth includes: growing a GaN monocrystal epitaxial layer on a sapphire substrate, bonding the GaN epitaxial layer onto a temporary substrate, lifting off the sapphire substrate, bonding the GaN epitaxial layer on the temporary substrate with a thermally and electrically conducting substrate, shedding the temporary substrate, and obtaining the composite substrate in which the GaN layer having a surface of gallium polarity is bonded to the conducting substrate. If the GaN layer on the sapphire substrate is directly bonded to the conducting substrate, after the sapphire substrate is lifted off, a composite substrate in which a GaN epitaxial layer having a surface of nitrogen polarity is bonded to the conducting substrate. The disclosed composite substrates have homoepitaxy and improved crystal quality; they can be used for forming LED and other devices at greatly reduces costs.
Yan T.,Peking University |
He J.,Peking University |
He J.,University of Central Florida |
Yang W.,Peking University |
And 7 more authors.
Physica Status Solidi (A) Applications and Materials Science | Year: 2015
We theoretically investigate the optical properties of conventional, normal (type A) parabolic and novel (type B) parabolic InGaN quantum well (QW) for blue light emitters. Two specially designed active layer structures by parabolic-shaped QW are proposed, and the optical characteristics of these two parabolic QW structures are calculated and compared to those of conventional QW structures. The electron-hole wavefunction overlap (Γe-hh) of type-B parabolic QWs is 2.8 times (69.6%) that in the conventional QW (24.8%), and the spontaneous emission rate is ninefold that of conventional QWs. The transparency carrier density of type-B parabolic QWs is much smaller than type-A parabolic or conventional QW. These results can be attributed to a higher indium index in the center of the type-B parabolic QWs, and that leads to better confinement of carriers wavefunctions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source
Xin X.-L.,Jiangsu University |
Zuo R.,Jiangsu University |
Tong Y.-Z.,Peking University |
Tong Y.-Z.,Sino Nitride Semiconductor CO. |
And 2 more authors.
Faguang Xuebao/Chinese Journal of Luminescence | Year: 2015
Surface initial growth process of GaN film in MOVPE is studied by DFT theory of quantum chemistry. By calculating the adsorption energies of GaCH3 and NH3 at main adsorption sites of GaN(0001)-Ga surface, it is found that energies of GaCH3 at four adsorption sites are similar, thus GaCH3 is easy to diffuse on the surface. The energies of NH3 at four adsorption sites are much different. The most stable adsorption site for NH3 is Top, and the large energy barrier exist for NH3 migrating from Top to other sites. Based on the energy analysis, the initial GaN surface growth mechanism is proposed for GaN(0001)-Ga surface, with NH3 and GaCH3 as growth precursor and ring structured core as final form. In the process of the ring structured core growth, the first GaN core growth need three NH3 and one GaCH3, which can be expressed as Ga(NH2)3. The second GaN core growth can use one existing N as coordination atom, so only two NH3 and one GaCH3 are needed. The two GaN core can be expressed as (NH2)2 Ga-NH-Ga (NH2)2. The third GaN core growth can use two existing N as coordination atoms, so only one NH3 and one GaCH3 are needed. The third GaN core forms a ring structure which can be expressed as Ga3(NH)3(NH2)3. The subsequent growth will repeat the process of the second and third core growth, so as to realize the continuous steps of GaN film growth. ©, 2015, Chines Academy of Sciences. All right reserved. Source