A novel InAlAs/InGaAs two-terminal real-space transfer diode

We report a two-terminal real-space transfer diode (RSTD) using a InAlAs/InGaAs heterojunction grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). By virtue of nonalloyed ohmic contacts as well as a sewer layer which is electrically separated from ohmic electrodes, a carrier density modulation and a strong negative differential resistance can be obtained. A peak-to-valley current ratio up to 140000 (1/spl times/10/sup 6/) at 300 (77) K are, to our knowledge, among the best for InAlAs/InGaAs structures. The proposed device also reveals sharp charge injection and broad valley range.