Non-degenerately doped lateral nanoscale p-n and p-i-n silicon-on-insulator devices have been fabricated and characterized at room temperature (297 K). In both types of devices, p-type Si substrate is used as a backgate to modify the potential in the top Si layer in both forward- and reverse-bias regimes. In the forward-bias regime, both types of devices exhibit negative differential transconductance (NDT), with the current peak position and level controlled by the backgate and anode voltage. In the reverse-bias regime, the devices exhibit a sharp current increase as a function of the backgate voltage, which is a signature of the band-to-band tunneling (BTBT) mechanism. These findings suggest that NDT and the sharp increase of current, induced by the contribution of the BTBT mechanism, can be achieved even in non-degenerately doped backgated diodes, which opens new possibilities for BTBT-based functionalities, benefiting from a simple design and CMOS compatibility. © 2021 The Japan Society of Applied Physics