有源层掺杂剂对Ga1-xAlxAs/GaAs双异质结发光管特性的影响

本文研究了由液相外延技术生长的GaAIAs/GaAs双异质结材料制成的发光管,有源层掺杂剂对器件特性的影响结果表明,器件结构和器件制作工艺相同的GaAIAs/GaAs发光管,有源层掺Si可获得较大的光输出功率,而频响特性<15MHz,波长在8700Å以上;对有源层掺Ge器件,光输出功率低于掺Si器件,而频响特性则>15MHz,波长可控制在8200Å~8500Å.深能级测量表明二者有不同的深能级位置,对掺Si(氧沾污)器件,Ec-ET≈0.29eV,而掺Ge器件ET-Ev≈0.42eV.两种掺杂剂对有源层暗缺陷的影响尚无明显区别.

DEPENDENCE OF CHARACTERISTICS OF GaAlAs/GaAs DH LEDS ON DOPANT OF ACTIVE LAYER

In this report the characteristics of GaAlAs/GaAs Burrus type DH LEDS for the active layer doped by Si or Ge are investigated. The GaAlAs/GaAs DH wafers used for fabrication of the LEDS were grown by LPE technique. The structure of a DH wafer consists of four layers. They are a n-Ga1-xAlxAs buffer layer (x=0.35), a active layer doped by Si or Ge, a Ge doped p-Ga1-xAlxAs confined layer (x=0.35), and a p-GaAs contact layer. The carrier concentration profile of the DH wafer was measured by the electrochemical C-V method. The device output power is about ≥2mW at 100mA.The experimental results are as follows:1. The output power of the GaAlAs/GaAs DH LEDS Si doped active layer are higher than that of Ge doped active layer.2. The cut-off frequence (fc) for the devices of Si doped active layer fc<15MHz at 100mA, for the devices of Ge doped active layer fc>15MHz.3. The emitting spectrum wavelength λ is≥8700Å and 8200Å~8500Å, for the Si doped and Ge doped devices, respectively.4. Using deep level measurement by DLTS and shot transient capacitance it was found that activation energy ΔE=0.29eV and 0.42eV for the Si doped and Ge doped devices respectively.5. The DLTS pattern of the devices for the Si or Ge doped does not show obvious difference.