A novel field emission microscopy method to study field emission characteristics of freestanding carbon nanotube arrays

Abstract

Field emission (FE) uniformity and the mechanism of emitter failure of freestanding carbon nanotube (CNT) arrays have not been well studied due to the difficulty of observing and quantifying FE performance of each emitter in CNT arrays. Herein a field emission microscopy (FEM) method based on poly(methyl methacrylate) (PMMA) thin film is proposed to study the FE uniformity and CNT emitter failure of freestanding CNT arrays. FE uniformity of freestanding CNT arrays and different levels of FE current contributions from each emitter in the arrays are recorded and visualized. FEM patterns on the PMMA thin film contain the details of the CNT emitter tip shape and whether multiple CNT emitters occur at an emission site. Observation of real-time FE performance and the CNT emitter failure process in freestanding CNT arrays are successfully achieved using a microscopic camera. High emission currents through CNT emitters causes Joule heating and light emission followed by an explosion of the CNTs. The proposed approach is capable of resolving the major challenge of building the relationship between FE performance and CNT morphologies, which can significantly facilitate the study of FE non-uniformity, the emitter failure mechanism and the development of stable and reliable FE devices in practical applications.

Gate‐Controlled Field Emission Current from MoS2 Nanosheets

“…FE is a quantum mechanical phenomenon in which electrons, extracted from a conductor or a semiconductor surface under application of an intense electric field, move in vacuum from a cathode to an anode. FE is used in a variety of applications, ranging from electrically‐operated floating‐gate memory cells, [ 26,27 ] electron microscopy, [ 28 ] and e‐beam lithography [ 29 ] to display technology [ 30 ] or vacuum electronics. [ 31 ]…”

Регистрация Зависимости Числа Эмиссионных Центров От Времени Как Инструмент Анализа Токовых Флуктуаций Полевых Катодов

“…В качестве примера редких методик можно назвать регистрацию светового и инфракрасного излучения полевых эмиттеров [17,18], регистрацию распределения центров эмиссии с помощью резистивного анодного покрытия [19], а также регистрацию пороговых напряжений включения по мере выгорания отдельных эмиссионных центров на картине свечения [20].…”

Coulomb explosion of vertically aligned carbon nanofibre induced by field electron emission

“…These issues can be resolved by our previously proposed FEM method based on poly(methyl methacrylate) (PMMA) thin lm with a microscopic camera. 26 The high sensitivity to low energy electrons of PMMA thin lm is able to record the FE performance of each CNF emitter from a CNF eld emitter arrays (FEA). The transparency of PMMA thin lm allows direct observation of the process and history of CNF emitter failure induced by FE.…”

“…Using this method, we are able to observe CNF emitter failure process, which exhibits a light emission followed by an explosion. 26 However, the mechanism behind this phenomenon demands further characterization and understanding.…”