Extended Data Fig. 9: Further thickness and temperature dependent OBJT measurements.

(a) Resulting amplification of devices with the same stack design as the one shown in Fig. 2d but with a higher doping concentration (5 wt.%) and base width of 10 nm and 50 nm, respectively. As expected, higher doping of the base and thicker base layer reduce amplification. From the change in amplification with base thickness W, an estimation for the diffusion length can be extracted via β ∝ coth(W/L_D). As an average from these calculations, a value of 50 nm can be extracted. (b) Temperature dependent differential amplification of devices with the same stack design as the one shown in Fig. 2d. The temperature dependent differential amplification of the device implies an increase in charge diffusion length with temperature which is consistent with a diffusion driven device. The temperature values in the legend are in K.