Effect of Substrate Conductivity on Si Self-Assembled Field Emission Arrays

Ungated high-density Si field emitter arrays are fabricated using a self-assembly technique based on the Langmuir-Blodgett deposition method. A uniform monolayer of silica nanoparticles is deposited to replace the lithography steps prior to etching vertical Si nanowires to form field emission arrays. High-density arrays are fabricated on Si substrates with two different substrate conductivities. It is observed that both types of arrays operate at low turn-on voltages (<40V) with a measured maximum current of 21 mA limited by measurement capability. Such high current is achieved at average electric fields of 2.5 V/μm and 7 V/μm for the substrate conductivities of 0.2 S.cm
^-1
and 3.3 mS.cm
^-1
, respectively. The fabricated low operating voltage field emission arrays achieve a maximum current density of 13 A/cm
²
.