Saturation measurements of electrically detected magnetic resonance in hydrogenated amorphous silicon based thin-film transistors

The saturational broadening of an electrically detected magnetic resonance signal in hydrogenated amorphous silicon has been observed in thin-film transistor structures. It was found that broadening of the resonance spectrum with increasing microwave power is caused by an enhanced local microwave field in the transistor due to strong coupling of th microwave field with the microstrip-like structure of the transistor. The field enhancement factor, which was estimated from saturation measurements, can reach 33 in a transistor with a channel width-to-length ratio of 500/10, demonstrating that the thin-film resonator is an effective tool for improving the detection sensitivity.