Donors and Acceptors Set the Majority - Semiconductor Physics: Bands, Doping, and Junctions Step by Step

The toy doping model checks majority type and margin only. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Donors make the toy majority ledger n-type

Two intrinsic electrons plus 6 donors gives 8 electrons against 2 holes, so the margin is 6.

n=2+6=8,\quad \Delta=6

Acceptors make the toy majority ledger p-type

Five acceptors with two intrinsic holes gives 7 holes against 2 electrons.

p=2+5=7

Equal donor and acceptor additions are a boundary case

Four donors and four acceptors give equal toy ledgers and margin 0.

\Delta=0\Rightarrow \mathrm{balanced}