Investigation of resonant interband tunneling structures using a three-band k · p model

A three-band k · p model (CLH model) considering realistically the coupling effects among the conduction band, light-hole band and heavy-hole band is proposed to investigate further the characteristics of the resonant interband tunneling structures. The tunneling current densities for k‖-independent and -dependent cases are calculated for comparison. It is found that the inclusion of the k‖ dependence is important in the discussion of the current-voltage (I–V) characteristics. The small peaks in low temperature I–V characteristics for GaSb/AlSb/InAs/GaSb/AlSb/InAs broken-gap interband tunneling (BGIT) structure with a 120 Å wide InAs well is owing to the substantial coupling between conduction band and heavy-hole band on nonzero k‖. The effects coming from the k‖ dependence also contribute to the rising of the first peak and the broading of the second peak in the low temperature I–V characteristics for BGIT structure with a 240 Å wide InAs well. A CLH model can interpret the particular phenomena in the I–V characteristics that cannot be explained by the two-band model, usually used in the investigation of the interband tunneling structures.