D. L. Keune

Liquid phase epitaxial In 1-x Ga x P 1-z As z /GaAs 1-y P y heterojunction 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 ( J_{th} \lsim 6.2 \times 10^{4} A/cm2) 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}) .