Abstract

For the purpose of integrating optical devices with conventional high-speed Si electronic devices, we proposed using the novel material of GaNAs for laser diodes (LDs) formed on Si wafers.¹ As GaNAs can be lattice-matched to Si, a drastic reduction in dislocation density is expected. However, early experiments^1,2 indicate that GaN_0.19As_0.81, lattice-matched to Si, might have a negative bandgap, as shown in Fig. 1. In this case, it will become a metal rather than a semiconductor. Thus, GaN_0.19As_0.81 cannot be used as a light emitting material. To overcome this problem, we proposed a GaNAs/GaNP strained-layer quantum well for the active layer of LDs formed on Si wafers.³ When the lattice constant of GaNAs is slightly larger than that of Si, a positive bandgap results. In this case, a large bandgap difference between GaNAs and GaNP can be achieved. The proposal, however, was merely qualitative. In this paper, the applicability of GaNAs/GaNP LDs formed on Si wafers is quantitatively discussed.

© 1995 IEEE