作　　者： ; ; ; (张勇）; (辛火平）; (杜武青）;

机构地区： 厦门大学物理与机电工程学院物理学系

出　　处： 《Journal of Semiconductors》 2003年第7期714-717,共4页

摘　　要： 在室温下测试了 Ga P1 - x Nx(x=0 .0 5 %～ 3.1% )混晶的喇曼散射谱 .在一级喇曼散射谱中观测到了 Ga P的L O(Γ)模和强度较弱的禁戒 TO(Γ )模以及 N的局域模 (495 cm- 3) .在 N组分较高的一组样品 (x=1.3%～ 3.1% )中 ,还观察到了位于 Ga P的 L O(Γ)模和 TO(Γ)模之间的由 N导致的 L O(N)模的喇曼频移 (387cm- 1 ) ,其强度随着N浓度的增加而增强 .在二级喇曼散射谱中 ,除了观测到布里渊区中心的声子散射峰 2 L O(Γ )外 ,还观测到了布里渊区边界的声子散射峰 2 L O(L )、2 TO(X)以及 L O(L ) +TO(X) .且边界散射峰的强度比中心散射峰更强 .另外在组分 x=0 .6 %和 x=0 .81%的样品中 ,还得到了诸如来自不同 NNi 对或 N原子簇团的局域模和由 N导致的新的散射峰 . The Raman scattering of GaP_ 1-x N_ x alloys ( x =0 05%～3 1%) grown by MBE are studied at room temperature.In addition to the strong GaP-like LO_1 mode and weak forbidden TO_1 mode,the second order Raman scattering of the zone-edge phonon (2LO_1(L) mode and 2TO_1(X) mode) as well as the scattering of the zone-center phonon are observed.Also,the nitrogen local mode (495cm -1 ) associated with the NN center and the so-called 'X' mode (387cm -1 ) of the LO phonon (manifested as a phonon sideband in the recombination of N bound excitons) are revealed in the Raman spectra of heavily N doped samples even under non-resonant excitation.In high N samples ( x >0 8%),multiple Raman modes are found at frequency,which is slightly lower than the local mode.These new modes are presumably associated with different NN or N cluster configurations.Additional Raman features,activated by N doping,at 604cm -1 and 681cm -1 ,are observed in the intermediate doping region.In general,a significantly higher N concentration is needed to activate a phonon mode in Raman under non-resonant excitation than to observe the phonon as a phonon sideband in PL.

关 键 词： 喇曼散射 混晶

领　　域： [理学] [理学]