A P-type silicon can be doped in the range from 1014 cm-3 to 1017 cm-3. If the device area is A = 1 cm × 1 cm, and the thickness of the P-type region is limited to tp = 200 μm. The minimum possible number of minority electrons in a neutral p-type region is ______.
[ni = 1.5 × 1010 cm-3 at 300 K]
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