InGaAsP/InP双异质结发光管暗缺陷的观察和研究

用红外电视选行扫描仪观察由不同P型掺杂剂的外延片制成的InGaAsP/InP双异质结发光管的暗缺陷,并研究了它的来源。比较了P型掺杂剂的种类和掺杂浓度对暗结构的影响。结果表明,掺Mg和掺In-Zn合金与重掺Zn器件相比,暗结构比例明显降低。Zn可能是暗缺陷的重要来源之一。器件在70℃,85℃条件下老化2000小时后,老化前无暗缺陷的某些器件亦有暗结构产生,但其生长率很慢。

OBSERVATION AND STUDY ON THE DARK DEFECTS IN InGaAsP/InP DOUBLE-HETEROSTRUCTURE LEDS

The dark defects in InGaAsP/InP DH LEDs are observed with an infrared line scanner. The dark structure appears before aging and it exists mainly in the form of dar kspot defect. The effect of the variety and concentration of the doping for p-InP confining layers on the dark defects is studied. The results show that the percentage of devices with dark defects is much lower for Mg or In-Zn doped devices than for Zn doped devices. It is believed that Zn is one of the important orign for the formation of dark defects. The growth rate of dark defects is studied both at room temperature and at 70--85℃. The results show that after aging for 15000 h at room temperature there are no dark defects newly appeared. But after agin for 2000 h at 70--85℃ some devices show newly formed dark structure with very slow growth rate.