Low threshold for optical damage in AlGaN epilayers and heterostructures
Low threshold for optical damage in AlGaN epilayers and heterostructures
复制标题
AlGaN 外延层和异质结构中的光学损伤阈值低
DOI：
10.1063/1.4834520
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发表时间：
2013
影响因子：
3.2
通讯作者：
M. Shur
中科院分区：
文献类型：
--
作者：
T. Saxena;G. Tamulaitis;M. Shatalov;Jinwei Yang;R. Gaska;M. Shur
持续时间远短于有效载流子寿命的激光脉冲在裸面和盖顶AlGaN脱膜和多个量子阱中引起永久光致发光（PL）猝灭和PL衰减率增强，其脉冲能量比导致表面熔化和降解的脉冲能量低一个数量级。相比之下，GaN涂层在相同的激发强度范围内没有光电化。PL光谱和衰变动力学表明，晶格加热不是引起AlGaN的变化的原因，而是由于在高非平衡载流子密度下发生的重组增强缺陷反应形成了非辐射重组中心。
Laser pulses with duration much shorter than the effective carrier lifetime cause permanent photoluminescence (PL) quenching and enhancement of PL decay rate in bare-faceted and capped AlGaN epilayers and multiple quantum wells at pulse energies about an order of magnitude lower than those causing the surface to melt and degrade. In contrast, GaN epilayers exhibit no photomodification in the same excitation intensity range. PL spectra and decay kinetics show that lattice heating is not responsible for the observed changes in AlGaN, which result from the formation of nonradiative recombination centers via recombination-enhanced defect reactions occurring at high nonequilibrium carrier densities.