Bioinspired Artificial Electronic Neurons Using Ultrathin Thermal Conductivity Graded Ge ₂ Sb ₂ Te ₅ Phase‐Change Materials

Phase‐change memory (PCM), characterized by its reversible transition between crystalline and amorphous phases, has emerged as a promising candidate for neuromorphic memory computing applications. However, conventional PCM devices lack an insufficient RESET/SET voltage ratio, which often leads to incorrect recording of the RESET state and limits computational accuracy. In this work, we report a Ge 2 Sb 2 Te 5 ‐based PCM device achieving a record‐breaking RESET/SET voltage ratio exceeding 10, significantly outperforming previously reported values below 5. This enhancement is enabled by an ultrathin (192 nm) architecture combined with a graded thermal conductivity design, which promotes a higher crystalline fraction, effectively reducing the SET voltage whereas maintaining a high RESET voltage. Furthermore, the nucleation and crystal growth mechanisms are systematically investigated, and the amorphous–crystalline phase transition is experimentally validated to enable rapid and reliable switching. These findings provide a new strategy for designing high‐performance PCM devices and pave the way for more precise and efficient neuromorphic computing systems.