High optical gain of I-VII semiconductor quantum wells for efficient light-emitting devices

In this work, we propose I-VII semiconductor hetero-structure quantum wells as active layers, which have a large exciton binding energy suitable for strong optical transitions in light-emitting devices. They are also closely lattice-matched to Si substrates, therefore free from defects. A multiband effective mass approach and non-Markovian model including the excitonic effects are used to study the optical gain. It is found that the optical gain of our design would be much higher than that of III-V nitride layers due to the inherent strong excitonic effects and negligible electrostatic fields within the active layers leading to highly efficient optical devices.