Controlling oxide-silicon semiconductor heterojunctions is a perpetual challenge in engineering electronic devices, including field-effect transistors and solar cells. We used advanced microscopy to perform an atom-by-atom deconstruction of the interface between doped zinc oxide and silicon, to elucidate the cause of Schottky barrier height pinning. The cause turns out to be the unexpected segregation of dopant at the interface—a phenomenon that may affect semiconductor heterojunctions generally.
R. Jaramillo, Amanda Youssef, Austin Akey, Frank Schoofs, Shriram Ramanathan & Tonio Buonassisi. Using atom probe tomography to understand Schottky barrier height pinning at the ZnO:Al / SiO2 / Si interface. Phys. Rev. Applied 6, 034016 (2016).