Study of Photoluminescence Mechanism of Rare Earth Ions in Compound-Semiconductors by Means of Magneto-Circular Photoluminescence

利用光弹调制器建立了磁圆二色吸收光谱(MCDA)和磁圆光致发光(MCpl)光谱测量系统，测量了25K下红宝石(Al_2O_3：Crt；3&gt；)的磁圆二色吸收光谱和磁圆光致发光光谱。根据配位场理论对这些光谱进行了分析。然而，这种分析不能解释观察到的R_1线的MCpl线型。在电弧炉中用浮区技术制备的CaS：Eu2&gt；单晶也测量了MCpl和MCDA的光谱。用化学输运技术生长了掺Tb的CuAlS_2单晶，将MCPL和MCDA中观察到的精细结构归结为f-d跃迁的三条零声子线和与ZPL相关的声子边线。在这些晶体中测得的光致发光光谱显示出一条宽阔的主体晶体的黄色谱带，并在该谱带上叠加了几条Tb^3-线。MCDA谱发现了Tb起源能级的激发态，而光致发光激发谱和光学吸收谱没有发现与Tb^&lt；3&gt；的激发态有关的谱线。因此，MCpl和MCDA技术是表征化合物半导体中稀土和过渡离子电子结构的有力工具。

A system of spectroscopic measurement for manetocircular dichroism of absorption(MCDA)and for magnatocircular photoluminescence(MCPL)was constructed using a photoelastic modulator.Using this technique, MCPL, as well as MCDA spectra in ruby (Al_2O_3 : Cr^<3+>) at 25 K were measured. These spectra were analyzed in terms of the ligand-field theory. However, the analysis failed to explain the observed MCPL lineshape of R_1-line.Spectra of MCPL and MCDA were also measured in a CaS : Eu^<2+> single crystal prepared by floating-zone technique in an arc-image furnace. Fine structures observed in MCPL and MCDA were assigned to three zero-phonon lines(ZPL)of f-d transition and phonon-side lines associated with the ZPL.Tb-doped single crystals of CuAlS_2 were grown by the chemical transport technique. PL spectra measured in these crystals showed a broad yellow band of host crystal and several Tb^<3+>-lines superposed on the band. Excited state of the Tb-origin energy level was found by the MCDA spectrum, although PLE(photoluminescence excitation)and optical absorption spectra showed no lines associated with the excited state of Tb^<3+>.Thus MCPL and MCDA techniques turns out to be a powerful tool for the characterization of electronic structures of rare-earth and transition ions in compound-semiconductors.