XHEMTs on Ultrawide Bandgap Single‐Crystal AlN Substrates (Adv. Electron. Mater. 3/2026)

Single-Crystal AlN Substrates In their Research Article (10.1002/aelm.202500393), Eungkyun Kim, Debdeep Jena, Huili Grace Xing, and co-workers demonstrate single-crystal high electron mobility transistors (XHEMTs) on bulk AlN substrates for the first time, delivering exceptional RF performance. AlN XHEMTs feature ultra-thin GaN channels fully strained between AlN layers, eliminating epitaxy-substrate thermal boundary resistance. By leveraging AlN's superior thermal conductivity, these XHEMTs promise to overcome thermal performance limitations.