The feasibility of diamond position sensitive detectors for deep UV light monitoring is reported. Based on voltage-division
principle, a very simple one-dimensional photosensitive structures have been developed exploiting the strong
variation of polycrystalline diamond conductivity under UV-light irradiation and dark conditions. Lumped and finite
elements analysis have been used to compare the theoretical expectations with the experimental results obtained under
excimer laser illumination. A complete characterization of such a 1D position sensitive device has been performed in
terms of: the beam intensity insensitivity (over three orders of magnitude); the output signal dependence on the beam
width; and the contact structure and its resistance influence on the device performances.
The photo-response of AlGaN based UV detectors to a 193 nm excimer laser radiation is presented. Two devices have
been tested and compared, a metal-semiconductor-metal (MSM) planar structure and a Schottky diode. These sensors
have already shown good performances in the 240-280 nm region under CW illumination and have been used for the
realization of 2D and linear arrays. Here the capability of these devices to detect the emission of a nanosecond pulsed
excimer laser is proven and the decay time and dependency on the beam's density of energy evaluated. The measured
transient response of the MSM device closely follows the nanosecond laser pulses, with a decay time shorter than 3 ns.
Conversely, the Schottky diodes showed a slower rise and decay kinetics principally limited by the coupling with the
junction capacitance. The decay curve of such a device has been analyzed on the basis of two decay mechanisms: the
second exponential decay has been found to be in the order of 40 ns. This slow kinetic has been attributed to the presence
of trap states localized at a distance from the conduction or valence band larger then the thermal energy of the carriers.
Both the realized devices do follow the Rose's law with a linear response at the lower beam fluxes (density of energy
4×10-5 - 0.2 mJ/mm2) and a transition to a sub-linear regime for higher fluxes.
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