2021/05/21 by Cherq Chua, Chua, Cherq, Chun Yun Kee +5
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #FOS: Physical sciences #Plasma Physics (physics.plasm-ph) #Quantum and electron transport phenomena #Semiconductor materials and devices
paper · pdf · doi:10.48550/arxiv.2105.10462
openalex publication_date 2021/05/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
For field emission (FE), it is widely expected that its emitting current density J will become space-charge-limited current (SCLC) due the built-up of charge in-transit within a gap spacing D biased at sufficiently large voltage V. In this paper, we reveal a peculiar finding in which this expected two-stage transition (from FE to SCLC) is no longer valid for FE not obeying the traditional Fowler-Nordheim (FN) law. %Such effect arises when the non-FN based emitters fails to inject sufficient %charge current at high voltage to sustain the SCLC. By employing a generalized FN scaling of ln(J/Vk) ∝ - 1/V, we show the existence of a critical exponent kc ≡ 3/2 where unusual behaviours occur for k < kc: (a) Only FE at small D (no transition to SCLC even at infinitely large V), and (b) Three-stage transition from FE first to SCLC then back to FE at large D. For any k > kc, the conventional two-stage transition from FE to SCLC will always occur for all D, which also includes the conventional FN law at k = 2. Using various unconventional FE models with k ≠ 2, we specifically demonstrate these peculiar transitions. Under a normalized model, our findings uncover the rich interplay between the source-limited FE and bulk-limited SCLC over a wide range of operating conditions.