INAS ANTIMONIDE-BASED RESONANT-TUNNELING STRUCTURES WITH TERNARY ALLOY LAYERS/

We have studied two modifications of mixed arsenide/antimonide resonan t tunneling structures, in which one of the binary components is repla ced by a ternary alloy. The first structure is based on an InAs/AlSb/G aSb resonant interband tunneling structure with the GaSb quantum well layer replaced by a GaAsxSb1-x alloy layer. The added As decreases the lattice constant in the well, and the resulting strain can shift the heavy hole subbands below the incoming electron energy. We find that t he negative resistance effect can be enhanced by properly adjusting th e splitting via the As concentration. A maximum enhancement in the pea k-to-valley ratio was obtained with a 10% As concentration in the diod es we fabricated. The second structure is a modification of a conventi onal InAs/AlSb double barrier structure, in which the AlSb barriers ar e replaced by AlxGa1-xSb with x almost-equal-to 0.5. In these structur es, the pronounced type II band alignment results in an entirely new t ype of current vs voltage characteristic exhibiting intrinsic current bistability (double-valued currents for a given voltage) instead of th e conventional voltage bistability. Peak-to-valley voltage ratios as h igh as 1.5 have been observed with current densities in the 10(5) A/cm 2 range.