InxGa1-xAs Injection Lasers

The possibility of forming high-quality p-n junctions directly on GaAs substrates is discussed along with a comparison of the electroluminescence (EL) properties of these junctions with those of p-n junctions with a compositionally graded layer. The In(x)Ga(1-x)As p-n junctions are prepared in a Ga-In-HCl-As4-H2 system by an ordinary vapor-phase growth technique on a Te-doped GaAs substrate. LEDs from both types of samples are fabricated to examine spontaneous EL properties. Fabry-Perot laser diodes are also fabricated from both types of samples. Typical dependences of emission intensities on pulsed current densities are presented and discussed. Experimental results show that In(x)Ga(1-x)As p-n junctions with compositionally graded layers exhibit nearly ten times better EL properties than those of the p-n junctions without graded layers.