Negative differential resistance of a delta-doping-induced double-barrier quantum-well diode at room temperature

A resonant-tunneling homojunction diode, which is a delta-doping-induced double-barrier quantum-well (D/sup 3/BQW) diode, is presented. The barrier uses the delta n/sup +/-i- delta p/sup +/-i- delta n/sup +/ structure. The current-voltage characteristics exhibit three sections of negative differential resistance (NDR) phenomena. At low bias, N-type NDR is demonstrated due to the resonant-tunneling effect. At higher bias, another N-type NDR appears due to the heating effect in the high electric field. As the external bias increases further, an S-type NDR is observed. This result is attributed to the impact ionization effect of thermionic electrons, and then trapping of holes in the maxima of the valence bands, resulting in barrier lowering and redistribution of voltage.<>