Revealing hidden phases and self-healing in antimony trichalcogenides and chalcoiodides

The prevalence of self-healing semiconductors is restricted to a few select cases, limiting understanding of the self-healing phenomenon. Herein, we report self-healing after photo-induced damage in antimony trichalcogenides and chalcoiodides, which are quasi-one-dimensional semiconductors with prospective applications in photovoltaics and electronic devices. We relate the self-healing to a photo-induced phase transition and the damaged state to a hidden phase from which the damaged semiconductors recover (self-heal). By using vibrational spectroscopy, we elucidate the intermediate species in the reaction. We suggest that the occurrence of bonding states at the bottom of the conduction band is central to promoting the hidden phase. Comparing four different materials with a similar crystal structure enables us to uncover the common structural feature that leads to the self-healing in these materials. Expanding the type and number of self-healing semiconductors, and uncovering the underlying solid-state reactions, will facilitate the development of self-healing electronic building blocks and devices.