Revealing Hidden Phases and Self-Healing in Antimony Trichalcogenides and Chalcoiodides

The prevalence of self-healing semiconductors is restricted to a few selected cases, limiting understanding of the phenomenon. Herein, we report self-healing following photoinduced damage in antimony trichalcogenides and chalcoiodides—quasi-one-dimensional semiconductors with prospective applications in photovoltaics and other electronic devices. We relate the self-healing to photoinduced phase transition (PIPT) and the ‘damaged’ state to a hidden phase from which the ‘damaged’ semiconductors recover (‘self-heal’). We elucidated intermediate species in the reaction and reaction dynamics using vibrational spectroscopy. Comparing four different materials with a similar crystal structure enabled us to uncover the common structural feature that leads to self-healing in these materials. By analyzing the chemical bonding, we rationalize the chemical reaction and point to bonding states at the bottom of the conduction band as central origins in propelling the hidden phase. Expanding the type and number of self-healing materials and uncovering the underlying solid-state reactions will facilitate the development of self-healing electronic building blocks for making animate electronic devices.