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Supported by analytical considerations and experimental verification, we demonstrate that thermionic electron current under partial space-charge condition follows the threehalves power Child-Langmuir law with a proportionality coefficient, j, that is material dependent and characterizes the emitter unambiguously. Such a partial space-charge regime has been assessed through experiments on parallel plane diodes with borondoped diamond films (with four different B/C ratios) as electron emitters at temperature of 1000 K. All current measurements have indicated a 3/2-power relationship on voltage but with distinct, material dependent coefficients j that were found to decrease with the work function of the samples tested.

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Diamond thin films chemically vapor deposited containing different B/C concentration in the range of 2000 -20 000 ppm were exposed to a β-ray dose of 0.8 -3000 Gy. The optically stimulated luminescence (OSL) response of previously irradiated samples was excited with light of 470 nm at room temperature. The OSL decay curves were measured and found them to be a function of the dose exposure. The remaining thermoluminescence (TL) glow curve after optical stimulation indicates the existence of main charge carriers trapped in traps located at 323 -523 K, meaning that the OSL emission appears to originate from charge trapped mainly at those traps related to the low temperature TL glow peaks. The results indicate that CVD diamond films perform well as OSL dosimeter for ionizing radiation.