Unstrained In0.3Ga0.7As/In0.29Al0.71As resonant tunnelling diodes grown on GaAs

The authors investigate the current-voltage characteristics of In/sub 0.3/Ga/sub 0.7/As/In/sub 0.29/Al/sub 0.71/As double-barrier resonant tunnelling diodes grown on GaAs substrates. These devices exhibit peak-to-valley current ratios as high as 7.6 and 19.5 at room temperature and 77 K, respectively. Two negative differential resistance regions are also observed for devices with larger well width. These results have shown that a high quality epilayer can be obtained despite the large lattice mismatch between In/sub 0.3/Ga/sub 0.7/As and GaAs. >