摘要
在国内首次通过微区光致发光结合拉曼散射的方法研究了GaP∶N五层结构的绿色发光外延片 ,用非破坏性的光学方法得到了载流子浓度的纵向分布 ,确定了发光最强的部位在P-区而且不同的样品有不同的光致发光强度随厚度的衰减曲线 ,以此为表征 ,从国内外样品的比较中查找出提高国产样品的改进方向。
Multi layer GaP wafers with different luminescence efficiency were investigated using microscopical optical methods. According to an interaction between the free carrier plasma and on the longitudinal optical lattice vibrations via their microscopical electric fields in GaP, an mixed plasmon phonon character is appeared. The carrier distribution has been determined from the fitting of the theoretical line shape to the observed spectra of the plasmon LO phonon coupled modes in the cross section of GaP diodes . The optical determination of electrical parameters has some advantages, it is not necessary to contact sample and the spatial resolution amounts to about 1 μm. The obtained results are in good agreement with those of electrical measurements. We have performed a synchronistic measurement in the cross section of GaP wafer by microscopical photoluminescence. The experiment demonstrates that there are different deep levels and red emissions in GaP substrate and p layer. The deep level in p local area has an obvious influence on PL intensity distance curve and on the luminescence efficiency. Therefore, it is important to improve red emission and to control deep level from growth condition. The result showed that the carrier distribution obtained from microscopical Raman spectra is related to the curve of PL intensity distance using microscopical photoluminescence. They argee reasonably with the distribution of doped impurities and existent defects in GaP substrate and epitaxial layers. It comes to the conclusion that the scanning Raman and photoluminescence technique is a powerful tool for the characterizations of GaP epitaxial layers as well as the diagnostics of LED devices.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2000年第3期200-204,共5页
Chinese Journal of Luminescence
基金
国家重大"863"基金资助项目!( 863 -715 -Z3 4 -0 1)
