WEEK 2 TASK 6, calculate the flatband voltage.

The accumulation capacitance becomes smaller and has the effect of reducing the measured capacitance as VG is gradually increased. on the other hand, when VG is equal to zero voltage(ideal case) or near to zero voltage(actual case), the condition of flatbands exists.

The equivalent circuit at flat-band shows below:

The semiconductors' capacitor is defined by the Debye length thus:

Then, the Debye length is given by:

So that

Compare with the curve in task 1,

when C=113.41 pF, V=0.265 V

that means the flatband voltage can be calculated as 0.265 V.