Exciton-Phonon Coupling of NN_3 Center in Heavily Nitrogen Doped GaP

通过光致发光谱研究了在 1 9～ 4 8K范围内掺氮浓度为 0 .1 2 %时的 Ga PN的 NN3束缚激子与声子的耦合 .直接计算了 NN3束缚激子的 L O,TO和 TA声子伴线的黄昆因子 S,除了 L O声子外 ,得到了 TO和 TA声子伴线的S因子在该温度范围内对温度的依赖关系 .计算表明 ,NN3的 L O,TO和 TA声子的 S因子均与温度无关 ,说明NN3的 L O,TO和 TA声子伴线与它们的零声子线具有相同的温度依赖关系 ,符合黄昆的多声子光跃迁理论Under heavy nitrogen doping,due to the “concentration quenching” effect,the full spectrum of the NN 3 center is revealed without the interference from the spectra of other higher energy centers.This investigation offers a direct proof for that all the phonon replicas are the phonon sidebands governed by the Huang Rhys’ multiphonon optical transition theory.国家自然科学基金 (批准号 :60 2 760 0 2 );; 厦门大学预研基金 (批准号 :Y0 70 0 5 )资助项目~

Photoluminescence Spectra of GaP_(1-x)N_x Alloys

【中文文摘】通过 Ga P1 - x Nx( x=0 .0 5 %～ 3.1%)混晶的低温光致发光 ( PL )谱 ,探讨了 N在不同组分 Ga Nx P1 - x混晶的发光特性中所起的作用 .在低组分 ( x =0 .0 5 %～ 0 .81%)下 ,Ga Nx P1 - x的 PL谱由 NNi 对及其声子伴线的发光组成 ;在高组分 ( x≥ 1.3%)下 ,NNi 对之间相互作用形成的与 N有关的杂质带导致了 Ga Nx P1 - x混晶的带隙降低 .同时 ,在 x=0 .12 %的 Ga Nx P1 - x中 ,得到了清晰的 NN3 零声子线及其声子伴线 ,从而直接证实了 NN3具有与孤立 N中心完全相似的声子伴线 . 【英文文摘】The photoluminescence spectra of GaP 1-xN x(x=0.05%～3.1%) alloys grown by MBE are studied at 17K.The evolution of the properties of the alloy with the increase of N composition is observed.The samples exhibit a series of sharp lines of NN i pairs bound excitons at low N concentration (x=0.05%～0.81%).While x increases above 1.3%,all the structures of spectra disappear and exhibit broadened emission and shift to the lower energy.The PL spectrum of GaP 1-xN x with x=0.12% exhibits clearly the phonon sideband,which shows directly NN 3 having the same phonon sideband spectrum as that of NN 1 and the isolated N center.国家自然科学基金 (批准号 :6 0 2 76 0 0 2 );; 福建省自然科学基金 (批准号 :A0 110 0 0 7)资助项