混晶GaAs_（1－x）P_x：N中N等电子杂质诱发的共振喇曼散射

Resonant Raman Scattering Induced by Isoclectronic Impurities in GaAs_(1-x)P_x:N Alloys

研究了混晶材料ＧａＡｓ＿（１－ｘ）Ｐ＿ｘ：Ｎ（ｘ＝０．７６，０．６５）中的共振喇曼散射，在背散射配置的（１００）晶向观察到“禁戒”的ＴＯ声子散射模．这一实验现象解释为在共振激发Ｎ＿ｘ杂质带的条件下，由于晶体对称性的喇曼选择定则失效，ＴＯ模成为喇曼活性．根据热猝灭规律，还给出区分共振喇曼散射和热荧光的一个实用判据．

A study of the resonant Raman scattering(RRS)by optical phonons that isinduced by excitons bound to nitrogen impurities in GaAs_(1-x)P_x:N(X=0.76,0.65)is reported.Unber resonant excitation into N_X band,strong Raman lines involving allowed LO and″forbidden″ TO for backscattering configuration from(100)surface are observed for the firsttime.This is interpreted as the breakdown of normal selection rule in the resonant Ramanscattering process.An operational criteria to differentiate the RRS from hot luminescence is given.