The document summarizes research on fabricating GaAs-based tunnel diodes on silicon substrates using aspect ratio trapping (ART). Key points: 1) GaAs tunnel diodes were integrated on silicon using ART, achieving world record performance for a tunnel diode on any material system. 2) ART enables heterointegration of materials like GaAs and prevents defects from lattice mismatch. 3) The best device demonstrated a peak valley current ratio (PVCR) of 43, the fourth highest reported for any tunnel diode.