Robust electrochemical modulation and environmental stability remain difficult to co-optimize with performance in organic semiconductors. Using a poly (propylenedioxythiophene) (ProDOT)-based polymer as an amorphous model conductor, we show that carbene-enabled and selective formation of covalent linkages between side-chains enhances thermo-chemical robustness while optimizing device performance. While pristine films of ProDOT degrade at ∼130 °C and dissolve in common solvents, cross-linked...