As an Al-free material system, the GaInAs/GaInP heterostructure has a
large conduction-band discontinuity. We,report the fabrication of GaIn
As/GaInP resonant tunneling diodes which exhibit current density-volta
ge characteristics with a peak-to-valley current ratio of 7.8 at 4.2K.
To our knowledge, this is the highest value obtained for this materia
l system.