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.