Liquid phase epitaxial In1-xGaxP1-zAsz/GaAs1-yPyheterojunction lasers

The growth and laser properties of In
1-x
Ga
x
P
1-z
As
z
/ GaAs
1-y
P
y
single heterojunction laser diodes are described. High-quality p-type In
1-x
Ga
x
P
1-z
As
z
layers are grown by liquid phase epitaxy (LPE) on n-type VPE GaAs
1-y
P
y
substrates of composition
y = 0.32 - 0.40
. Laser operation (77 K) of these quaternary-ternary heterojunctions is demonstrated at shorter wavelengths (<6300 Å) and lower thresholds (
J_{th} \lsim 6.2 \times 10^{4}
A/cm
²
) than comparable GaAs
1-y
P
y
homojunctions. The increase observed in threshold current (
5x
) between
y = 0.38
and
y = 0.40
GaAs
1-y
P
y
substrates is attributed to the usual effect of E
X
approaching
E_{\Gamma}
near the direct-indirect transition. From the well-defined cavity mode structure observed on these hetero-junctions, data are obtained at relatively high energy on the index dispersion quantity
{n - \lambda(dn/d\lambda)}
, which increases monotonically with photon energy and provides a reference for the distinctly different behavior observed on N-doped GaAs
1-y
P
y
(h_{\nu} \sim E_{\Gamma} \sim E_{N})
.