The field emission of carbon-in-Al4O4C nanoneedles and its failure mechanism: high-field induced shell cracking and chemical decomposition

摘要

Although ceramic Al_4O_4C has recently been found to have interesting optical properties, its low conductivity makes it difficult to be used in fields related to electron transport. Here, we achieved carbon-in-Al4O4C core-shell nanoneedles via a one-step chemical vapor deposition method. The core with the form of few-layer graphene embedded in amorphous carbon improves the electron transport largely, as the I-V measurement is based on a single nanowire. Good field electron emission behavior was observed in these nanoneedles. Noticeably, when a large electric field was loaded, the nanoneedle failed in two manners, i.e. zippered dispassion between the core and shell, and chemical deposition of the Al_4O_4C shell into metastable δ-Al_2O_3. These results help to broaden the application field of Al_4O_4C and understand its physicochemical behavior under extreme conditions.