氮化物耦合量子阱中的二次谐波产生极化率:压电与自发极化效应

SECOND-HARMONIC GENERATION SUSCEPTIBILITIES OF A NITRIDE COUPLING QUANTUM WELL: EFFECTS OF PIEZOELECTRICITY AND SPONTANEOUS POLARIZATION

理论考察了存在强内建电场的纤锌矿GaN/InxGa1-xN耦合量子阱体系的二次谐波产生(SHG)特性,结果发现共振SHG系数达到了10-7m/V的量级,SHG系数对耦合量子阱的结构与掺杂组份呈现非单调的依赖关系.结果还表明,通过选择小尺寸垒宽与大尺寸阱宽的耦合量子阱,并适当降低掺杂组份,可在氮化物耦合量子阱中获得较强的SHG极化率.

The second-harmonic, generation （SHG） susceptibility of a wurtzite GaN/In, Ga1-x N coupling quantum well （CQW） with strong built-in electric field was theoretically investigated. The calculated results reveal that the resonant SHG coefficients reach the order of magnitude of 10^-7 m/V and the SHG coefficients are not monotonic functions of the well width, barrier width and the doped concentration of the CQW systems. Our results also show that a strong SHG coefficient can be obtained in the nitride CQW by choosing optimized structural parameters and doped fraction. n