Unsubstantiated p ‐Type Semiconductivity in 2D Ruddlesden–Popper Cs ₂ PbI ₂ Cl ₂ Perovskite

Abstract This Comment critically examines the reported p‐type semiconductivity in 2D Cs ₂ PbI ₂ Cl ₂ perovskite [ Adv. Funct. Mater . ​ 2025 , 35 , 2419709]. Quantitative analysis reveals insulating behavior, with the Fermi level positioned 1.35 eV above the valence band maximum yielding effectively zero‐hole concentration. The deep valence band maximum (‒6.12 eV) exceeds established p‐type doping thresholds, creating a 0.44 eV barrier that impedes hole extraction from CsPbI ₃ . Simulation parameters used to justify performance improvements contradict experimental band positions. Observed device enhancements may be attributed to interfacial passivation rather than unsubstantiated p‐type semiconductivity, highlighting the critical need for direct carrier characterization in emerging semiconductor research.