Independent tuning of work function and field enhancement factor in hybrid lanthanum hexaboride-graphene-silicon field emitters
Abstract
The authors report the experimental demonstration of independent control over work function and field enhancement factor in hybrid field emitters using a lanthanum hexaboride (LaB6) nanoparticle low-work function coating on monolayer graphene on microfabricated silicon arrays. A critical challenge in field emitters is combining the scalability and uniformity of silicon microfabrication with low-work function materials. Specifically, the authors engineer the field enhancement through microfabrication of the underlying silicon wafers and control the work function by the transfer and deposition of monolayer graphene and LaB6 nanoparticles. Using this coating, the turn-on electric field, defined as the electric field required for 10 μA/cm2 of emission current density, drops by 5× from 12.5 to 2.6 V/μm. To further analyze these results, the authors carried out detailed electronic and structural characterization of the hybrid emitters to experimentally determine the work function and model the field enhancement factor of the physical structure. Using these coupled simulations and experiments, the authors show that the work function and field enhancement factor can be independently controlled, potentially enabling ultralow turn on, uniform, and stable emitters.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 01, 2017
- Source ID
- 10.1116/1.5001324
Entities
People
- Andrew Clough
- Ayush Garg
- Debarghya Sarkar
- Fatemeh Rezaeifar
- Louis Blankemeier
- Nirakar Poudel
- Qingfeng Lin
- Rehan Kapadia
- Stephen B Cronin
- Tracy M Mattox
- Xiangyu Chen
Organizations
- Air Force Office of Scientific Research
- Lawrence Berkeley National Laboratory
- National Science Foundation
- University of Southern California