Light-Emitting Mechanism of Rare-Earth Doped III-V Compound Semiconductor and the Light-Emitting Devices of Carrier Injection Type

为了阐明液相外延（LPE）、热扩散和离子注入三种方法制备的样品的发光机理，研究了稀土掺杂III-V族化合物半导体和Si的光致发光（PL）和电致发光（EL）光谱。我们观察到了具有特殊峰的发光光谱，这些峰与稀土原子内部4f-4f跃迁有关（与半导体的光学性质或能带结构无关）。稀土掺杂的III-V族化合物半导体体系是用于新型光电器件和EL器件（例如激光二极管和发光二极管）的有前途的材料。 1液相外延(LPE)通过PL或EL测量GaAs中不同Yb化合物如YbF_3、YbP，获得了1000nm左右的Yb^<3>相关发光。对于EL样品，GaAs中的稀土可以通过载流子注入来激发。GaAs:YbF_3和GaAs:YbP的Yb^<3>相关发射相对较宽。 InP : YbCl_3 是因为 Yb^<3 > 与 GaAs 中的一些缺陷或杂质形成复合中心。2 热扩散 Si 中的 Er^<3 > 离子在 1540 nm 附近获得了与 Er^<3 > 相关的发光，光致发光激发光谱 (PLE) 光谱由直接激发 Er^<3 > 离子引起的尖峰组成。对于 InP : Er，没有观察到 Er^<3 > 相关发光。3离子注入InP：Yb和Si；与LPE和热扩散相比，Er表现出强烈的稀土相关发射。对于InP：Yb，当Yb^<3>离子被InP带隙以下的光子能量激发时，Yb^<3>相关发射很强，因为通过缺陷能级发生了到Yb^<3>离子的新的有效能量转移过程。

Photoluminescence (PL) and electroluminescence (EL) spectra of rare earth doped III-V compound semiconductors and Si were investigated in order to clear the light emitting mechanism of the samples prepared by three methods such as liquid-phase epitaxy (LPE), thermal diffusion and ion-implantaion. We observed the luminescence spectra with peculiar peaks which are related to the internal 4f-4f transitions of the rare earth atoms, (which are independent of the optical properties or the band structure of semiconductor). The rare earth doped III-V compound semiconductor systems are promising materials for a new type of optoelectronic devices and EL devices such as laser diode and light-emitting diode. The following results were obtained.1 Liquid-phase epitaxy (LPE)The Yb^<3+>-related luminescence around 1000nm was obtained through the PL or EL measurements from different Yb compounds as YbF_3,YbP in GaAs.For EL samples, the rare earth in GaAs can be excited by carrier injection.The Yb^<3+>-related emission of GaAs : YbF_3 and GaAs : YbP was relatively broad compared with InP : YbCl_3 because the Yb^<3+> forms complex centers with some defects or impurities in GaAs.2 Thermal diffusionThe Er^<3+>-related luminescence around 1540nm was obtained from the Er^<3+>ions in Si, and the photoluminescence excitation spectroscopy (PLE) spectra consisted of sharp peaks which were caused by the direct excitation of Er^<3+>ions.For InP : Er, Er^<3+>-related luminescence was not observed.3 Ion-implantationInP : Yb and Si ; Er showed intense rare-earth related emission compared with LPE and a thermal diffusion.For InP : Yb, when Yb^<3+>ion was excited by the photon energy below the InP-band-gap, Yb^<3+>-related emssion was strong because the new efficient energy transfer processes to Yb^<3+> ions occurred through the defect energy levels.