Preservation of Isolated-Material Band Alignments at Realistic Interfaces

Determine whether band alignments predicted from isolated perovskite and P3HT components are preserved after realistic interface formation or transform into different heterojunction types.

Background

The paper identifies the relationship between perovskite composition, interface structure, and band alignment as an unresolved challenge. Vacuum-referenced band-edge positions from isolated materials provide useful predictions, but interface formation can introduce structural relaxation, orbital hybridization, and surface-dependent effects that alter the electronic structure.

The unresolved issue is whether isolated-component predictions remain valid for realistic P3HT/perovskite heterostructures or whether interface formation changes the junction from one alignment class—Type I, Type II, or Type III—to another. The calculations in the paper examine selected tin-based interfaces and therefore provide representative evidence rather than a general resolution for all compositions and interface structures.

References

Similarly, it remains unclear whether band alignments predicted from isolated components are preserved after realistic interface formation or whether they change into different heterojunction types.

— Composition and Surface Termination Control Band Alignments in P3HT/Perovskite Heterostructures  (2609.09566 - Alidoust et al., 9 Sep 2026) in Introduction, paragraph beginning “A major unresolved challenge”