Description: This book explores the "heterojunction" as a unifying concept that bridges energy materials and information devices, redefining how structure and function interact across disciplines. Beyond a physical boundary, the heterojunction enables electronic state reconstruction, interface field regulation, and multidimensional signal coupling, driving the transition from single-material functionality to interface-governed behavior. In energy storage, engineered heterostructures between one- and two-dimensional nanomaterials achieve synergistic electron-ion transport, improving rate performance and cycling stability in sodium-ion batteries. Extended to multicomponent systems, heterojunction interfaces guide charge transfer and energy conversion through band alignment and interface coupling. In optoelectronic and thermoelectric systems, van der Waals heterointerfaces between layered semiconductors and conductive phases enable precise carrier and band control, enhancing photoresponse and thermoelectric efficiency. In neuromorphic devices, multidimensional heterojunctions integrate electrical, optical, and polarization signals to emulate synaptic plasticity and neural memory.
