P型掺杂剂对InGaAsP/InP双异质结发光管特性的影响

本文研究了限制层中掺杂剂对InGaAsP/InP双异质结发光管特性的影响。结果表明限制层掺In-Zn合金或掺Mg的器件不易发生p-n结偏位,器件具有单一的长波长光谱峰,正常的I-V特性以及暗结构出现率低的特性,而限制层掺Zn当浓度≥1×1018cm-3时,外延片易发生p-n结偏位,导致器件的异常特性。并观察到在扩散结器件中,在85℃长时间老化过程中,有p-n位置移动现象发生。

EFFECT OF THE p-TYPE DOPANT ON THE CHARACTERISTICS OF THE InGaAsP/InP DH LED’ s

The InGaAsP/InP double-heterostructure (DH) light emitting diodes are interesting for the use in optical communication systems operating in the wavelength range of l-1.6μm. In present work, we have investigated the dependence of characteristics of LED operating at 1.27-1.3μm on the devices structure and fabrication method. Particularly, we have examined the proporties of the heterostructure prepared by using different dopants In-Zn, Mg and Zn, for the p-InP confining layer. The DH wafer was grown by liquid-phase epitaxy on (100) n-type (Sn doped) substrate. The DH structure consists of a 5-6μm thick n-type (Sn doped) InP buffer layer,an undoped inGaAsP active layer, a 1-2μm thick Zn, In-Zn or Mg-doped InP confining layer. The position of p-n junction and concentration profile of DH wafers were measured by electrochemical C-V method. The InGaAsP/InP DH LED’s have been fabricated. The output power of the devices are 1-2mW (at 100mA), the emitting wavelength λ is 1.27-1.3μm.The results show that using the In-Zn alloy or Mg as p-type dopant, location of p-n junction can be accurately controlled these devices have normal parameters, but using Zn as the p-type dopant the misplaced p-n junction is observed, and these devices have an anomal characteristics.