InP tunnel junctions grown by atomic layer molecular beam epitaxy on InP and InP-on-Si substrates

Abstract

p++/n++ InP tunnel diodes have been fabricated for the first time on InP and Si substrates by solid source Atomic Layer Molecular Beam Epitaxy (ALMBE) at low temperature. The high peak current density exceeding 200 A/cm2 and the low specific resistance exhibited in these diodes indicate that they are appropriate to use as optically transparent interconnects in InP/Ga0.47In0.53As tandem solar cells. This is a very promising result for the use of solid source ALMBE for fabricating these tandem solar cells with a technological process compatible with low temperature technologies, as the conventional silicon technologies.