Photovoltaic detection of magnetic resonance in a‐Si:H solar cells

The detection of magnetic resonance via the photovoltage or photocurrent (PDMR) is a sensitive method for investigating recombination in solar cells, particularly amorphous semiconducting structures. For samples which also show luminescence the results can be directly related to optically detected magnetic resonance (ODMR) measurements so that a comparison can be made of the relative importance of the various recombination processes on the two effects. We outline in this paper the results of comprehensive studies of steady‐state and time resolved PDMR and a comparison of PDMR and ODMR results, particularly the temperature dependence of the signals, indicates that different mechanisms are responsible for the resonance signals observed using these techniques.