Photoconductive resonance in silicon: Theory and experiment

Measurements have been made of light-induced resonant centers at silicon surfaces which behave as power emission rather than absorption centers as applies to normal electron-paramagnetic resonance EPR. The phenomenon is analyzed as a form of photoconductive resonance, called PCR, and a theroretical expression is derived. The EPR signal then expected from PCR centers at sufficiently low power has been detected for the first time. The dependence on temperature and power of the signals from the PCR centers agrees well with the predictions from theory. The sensitivity of detection of PCR centers is found to be over 30 times that of EPR centers.