Experimental calibration of the temperature dependence of the heterojunction bandgap in III-V tunneling devices

摘要

The capability to achieve sub-60 mV / dec subthreshold swings through quantum mechanical (QM) band-to-band tunneling (BTBT) has established the tunnel field-effect transistor (TFET) as an important candidate to drive future ultra-low power logic applications [1], [2]. Currently, most state-of-the-art TFET devices use III-V compounds as their active region material [3]-[5]. This is motivated by the direct nature of their bandgap and the possibility to combine two different materials in a heterostructure configuration to obtain a small effective bandgap E_g,eff at the the heterojunction. However, the temperature dependence of the effective bandgap and how it relates to the constituent compound materials has not yet been resolved. In this work, we calibrate the temperature dependence of the effective bandgap of a GaAs_0.5Sb_0.5(GAS)/In_0.53Ga₀₄₇ As (IGA) heterostructure using the current-voltage characteristics of a p-i-i-n GAS/IGA heterostructure Esaki diode [6], and we present calibrated temperature-dependent TFET predictions.