Al/sub 0.48/In/sub 0.52/As/Ga/sub 0.47/In/sub 0.53/As resonant tunnelling diodes with large current peak/valley ratio

Resonant tunnelling diodes consisting of an MBE-grown AlInAs barrier on each side of a lattice-matched GaInAs well have been fabricated. Current peak/valley ratios up to 7.1 and 39 have been measured at 300 K and 77K, respectively. These represent the largest values reported to date in any double-barrier, single-well device. The enhanced peak/valley ratio has been attributed to thick barriers (72 A) and wide, undoped GaInAs spacer layers (400 A).