Monatomic Sb thin films alloyed with Sb2S3 enables superior thermal stability and resistance drift by spontaneous self-decomposition

Abstract

Monatomic Sb thin films can eliminate the risks of compositional partitioning, but it normally crystallizes instantly and fails to maintain amorphous state at room temperature. Here, we prepared Sbx (Sb2S3)100-x thin films. The materials consist of pure Sb with low resistance drift and chalcogenide Sb2S3 with high thermal stability. It is found that the Sb64·8(Sb2S3)35.2 thin film possesses the advantages of these two compounds. The thin film showed good phase-change ability with an ultralow resistance drift coefficient of 0.006, much lower than conventional Ge2Sb2Te5 (0.076). Moreover, it also exhibited a better amorphous thermal stability. These improvements are closely related to the hybrid nanostructure of Sb crystals and Sb–S phase by spontaneous self-decomposition in the Sb-rich Sb–S material. Our work thus demonstrates that the binary Sb-rich Sb–S thin film can become a promising alternative to replace the conventional Ge2Sb2Te5 thin film with potential for neuromorphic synaptic devices.