Sensitivity boosting in solid-state NMR of thin organic semiconductors by a paramagnetic dopant of copper phthalocyanine

► Paramagnetic doping enhances 31P CPMAS intensities of thin films by a factor of 1.7. ► Most 1H spins in the 50 to 100 nm organic films are polarized by 1H-1H spin diffusion. ► No harmful effect of paramagnetic doping is observed. ► 1H magnetizations are quickly produced by paramagnetic relaxations. ► 1H magnetizations are distributed among the organic films by 1H-1H spin diffusion.