Polycrystalline diamond position sensitive detector for excimer laser UV radiation

Abstract

To overcome any difficulty related to the fabrication of diamond ultraviolet (UV) sensors based on p–n junction, in this work we describe the realisation and characterisation of a very simple chemical vapour deposited diamond position sensitive detector based on a voltage-division structure. The photosensor, tested under UV excimer laser illumination, shows a non-linearity of the output signal vs. the beam position of approximately 6% but the response repeatability under stable excitation conditions indicates an rms signal fluctuation as low as 1%. A very low sensitivity to light intensity variation has been also evidenced. Moreover, the device shows a high stability and preliminary results seem to indicate a good robustness to repetitive use. Compared to silicon, the high thermal conductivity and the large threshold energy for radiation damage of diamond would largely extend the lifetime of the device under high intensity UV irradiation.