Electric cars flip their power switches on and off thousands of times a second. Every flip wastes a little energy as heat, and so does the switch's resistance while it is on. A better material wastes less, so the car goes farther and needs a smaller radiator. Diamond is also the only one that gets better when it is hot.

Per switch, P = I²R_on,sp/A + ½C_oss,spAV²f. Choosing the die area A to minimize P gives P = 2IV√(fR_on,spC_oss,sp/2): conduction and switching losses come out equal, and the material's merit is √(R·C). The required heat-sink thermal resistance is (T_j,max − T_ambient)/P.

Inputs come from adamas.converter via data/site.json and are tested to agree with the Python within 1%. R_on(T) includes lattice-mobility exponents and, for bulk-doped diamond, the rise of boron ionization with temperature; the measured diamond device (a lateral hole-gas MOSFET) has no ionization gain. Gate charge, reverse recovery, and GaN dynamic R_on are not modeled; ceilings are package and reliability limits (chapter E9).