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Self‐healing (SH) of (opto)electronic material damage can have a huge impact on resource sustainability. The rising interest in halide perovskite (HaP) compounds over the past decade is due to their excellent semiconducting properties for crystals and films, even if made by low‐temperature solution‐based processing. Direct proof of self‐healing in Pb‐based HaPs is demonstrated through photoluminescence recovery from photodamage, fracture healing and their use as high‐energy radiation and particle detectors. Here, the question of how to find additional semiconducting materials exhibiting SH, in particular lead‐free ones is addressed. Applying a data‐mining approach to identify semiconductors with favorable mechanical and thermal properties, for which Pb HaPs are clear outliers, it is found that the Cs2AuIAuIIIX6, (X = I, Br, Cl) family, which is synthesized and tested for SH. This is the first demonstration of self‐healing of Pb‐free inorganic HaP thin films, by photoluminescence recovery. [ABSTRACT FROM AUTHOR]

Tin‐based perovskites are promising alternative absorber materials for lead‐free perovskite solar cells but need strategies to avoid fast tin (Sn) oxidation. Generally, this reaction can be slowed down by the addition of tin fluoride (SnF2) to the perovskite precursor solution, which also improves the perovskite layer morphology. Here, this work analyzes the spatial distribution of the additive within formamidinium tin triiodide (FASnI3) films deposited on top of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transporting layers. Employing time‐of‐flight secondary ion mass spectrometry and a combination of hard and soft X‐ray photoelectron spectroscopy, it is found that SnF2 preferably accumulates at the PEDOT:PSS/perovskite interface, accompanied by the formation of an ultrathin SnS interlayer with an effective thickness of ≈1.2 nm. [ABSTRACT FROM AUTHOR]

The interfacial electronic structure between oxide thin films and organic semiconductors remains a key parameter for optimum functionality and performance of next-generation organic/hybrid electronics. By tailoring defect concentrations in transparent conductive ZnO films, we demonstrate the importance of controlling the electron transfer barrier at the interface with organic acceptor molecules such as C60. A combination of electron spectroscopy, density functional theory computations, and device characterization is used to determine band alignment and electron injection barriers. Extensive experimental and first principles calculations reveal the controllable formation of hybridized interface states and charge transfer between shallow donor defects in the oxide layer and the molecular adsorbate. Importantly, it is shown that removal of shallow donor intragap states causes a larger barrier for electron injection. Thus, hybrid interface states constitute an important gateway for nearly barrier-free charge carrier injection. These findings open new avenues to understand and tailor interfaces between organic semiconductors and transparent oxides, of critical importance for novel optoelectronic devices and applications in energy-conversion and sensor technologies. [ABSTRACT FROM AUTHOR]

The electronic structure of a bi-layer hole extraction contact consisting of nickel oxide (NiO x) and molybdenum trioxide (MoO3) is determined via ultraviolet and X-ray photoemission spectroscopy. The bi-layer presents ideal energetics for the extraction of holes and suppression of carrier recombination at the interface. The application of the NiO x/MoO3 bi-layer as the anode of organic bulk heterojunction solar cells based on PCDTBT/PC71BM leads to improved device performance, which is explained by an intricate charge transfer process across the interface. [ABSTRACT FROM AUTHOR]