【中文文摘】室温下采用背散射几何配置,在近共振条件下测量GaAs1-xNx混晶的喇曼散射谱.由于N原子的引入,导致类GaAs的LO1、TO1声子和类GaN的LO2声子线宽变大,禁戒的TO1声子变为喇曼活性;随着N组分的增加,TO1声子强度增大、LO1声子有红移的趋势、LO2声子有蓝移的趋势,根据它们随N组分x移动的速度推断出样品不存在应变效应.另外还讨论了布里渊区边界声子LA(L)与LO(L)、二级喇曼散射谱声子LO2、LO1+LA1(L)以及2LO1随N组分x增大的变化趋势.
【英文文摘】Near-resonant back-scattering Raman studies of GaAs_(1-x)N_x(x=0.1%～1.7%)alloys at room temperature are reported.The Raman spectra exhibits two-mode behavior.With the N incorporation,the full widths at half maximum (FWHM)of GaAs-like LO_1 mode and TO_1 mode are broader than those of the pure GaAs.The forbidden TO_1 mode is activated and its intensity is enhanced with increasing the N content, while the ratio of I_(TO1)/I_(LO1) remains constant.The red-shift of the LO_1 mode is smaller and the blue-shift of the GaNlike LO2 mode is larger than those reported in previous studies ,which indicate that the alloying effect instead of
the strain effect exists in the alloys. The trends of LA( L ) 、LO( L ) 、LO2 、LO1 + LA1 ( L ) 、2LO1 phonons with increasing the N composition are also disscussed. These trends are attributed to the breakdown in the zinc blende国家自然科学基金(60276002);; 福建省自然科学基金(A0110007)资
