Study of peak and valley currents in double quantum well resonant interband tunnel diodes

Peak and valley current densities of double quantum well (DQW) resonant interband tunnel (RIT) diodes with well widths of 20, 30, 40 and 60 angstrom are experimentally investigated and compared with those of non-resonant heterojunction tunnel diodes. For the 40 angstrom well diode peak current density at resonance increases by an order of magnitude in comparison with the 20 angstrom and 30 angstrom well diodes, and is of the same order of magnitude as for the non-resonant tunnel diodes. The valley current for the 40 angstrom well diode is an order of magnitude smaller than in the non-resonant diodes. Peak-to-valley (P/V) current ratios for the 20 angstrom well diodes are the same as for the non-resonant diodes. A theoretical analysis of the observed phenomenon is presented, along with a discussion of the optimization of the P/V ratio, which is based on the properties of double resonance and double antiresonance in a DQW three-barrier system. The analysis predicts the possibility to increase the peak resonant current and P/V ratio by orders of magnitude. For this purpose, new DQW RIT structures with three matched barriers are suggested.