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

摘要

Although ceramic Al4O4C 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 Al4O4C shell into metastable delta-Al2O3. These results help to broaden the application field of Al4O4C and understand its physicochemical behavior under extreme conditions.