Thin-film negative differential resistance and neuronal circuit

A monolithically integrated pair of semiconductor devices on an insulating substrate, comprising:

• a heterojunction field-effect transistor (HJFET) including first hydrogenated silicon-based contacts disposed on a first portion of a semiconductor material of the insulating substrate;
• and
• a heterojunction bipolar transistor (HBT) including second hydrogenated silicon-based contacts disposed on a second portion of the semiconductor material of the insulating substrate;
• wherein a portion of multi-layer source and drain contacts of the HJFET and a multi-layer base contact of the HBT include a same material, and a portion of multi-layer emitter and collector contacts of the HBT partially overlap all of the conductive layers of the multi-layered base contact and a multi-layer gate contact of the HJFET partially overlaps the multi-layer source and drain contacts;
• wherein the HJFET and the HBT are integrated to create negative differential resistance by forming a lambda diode.