Spectral responsivity measurements of photoconductive diamond detectors in the vacuum ultraviolet region distinguishing between internal photocurrent and photoemission current

Spectral responsivities of photoconductive diamond detectors were measured based on a standard detector calibrated by a rare-gas ionization chamber in the wavelength range from 10 to 60 nm using synchrotron radiation. The photoemission current component was measured separately from the internally generated photocurrent component by using two electrical measurement configurations and by changing the polarity of the applied voltage to the detector. The photoemission current contribution to the total output current was not negligible but dominant in wavelengths longer than 40 nm. On the other hand, the internal photocurrent played a major role in wavelengths shorter than approximately 25 nm. (C) 2005 American Institute of Physics.