Due to the introduction of morphological control, the excitons are pushed towards the regions with higher stress. In addition, combined with intrinsic electric field, a spatial separation of photo-excited electrons and holes is achieved.
Using alloying and/or twisting between layers to achieve the type I direct bandgaps vertical heterojunction in transition metal dichalcogenide family of MX2 (M = {Mo, W}, X = {S, Se}).
Composition-induced type I and direct bandgap transition metal dichalcogenides alloy vertical heterojunctions