Understanding the role of interface in advanced semiconductor nanostructure and its interplay with wave function overlap

As the proportion of interfaces increases rapidly in nanomaterials, properties and quality of interfaces hugely impact the performance of advanced semiconductors. Here, the effect of interfaces is explored by comparatively studying two InAs/AlSb superlattices with and without the thin InAsSb layers inserted inside each InAs layers. Through strain mapping, it indicates that the addition of interfaces leads to an increase of local strain both near interfaces and inside layers. Meantime, owing to the creation of hole potential wells within the original electron wells, the charge distribution undergoes an extra electron-hole alternating arrangement in the structure with inserted layers than the uninserted counterpart. Such a feature is verified to enhance electron-hole wave function overlap by theoretical simulations, which is a must for better optical performance. Furthermore, with an elaborate design of the inserted layers, the wave function overlap could be boosted without sacrificing other key device performances.