Impact of nitrogen induced defect dynamics on UV response of diamond photodetectors

Abstract This work correlates the ultraviolet (UV) current response of single-crystal diamond photodetectors to the lifetimes of nitrogen-induced color centers. Single-crystal diamond photodetectors are fabricated and characterized by optical and electrical measurements. The optical characterizations include Raman spectroscopy, Photoluminescence spectroscopy (PL) and the Time Resolved Photoluminescence (TR-PL) measurements. The electrical characterizations include the capacitance-voltage (C–V), current-voltage (I–V), and UV response current measurements. As observed from the photocurrent studies, the magnitude of the current response rises up to five order in the voltage range ±100V in comparison to the dark condition. The charge carrier dynamics of the dominant color centers contributing to the response have been analysed quantitatively through UV response, PL and TR-PL measurements. TR-PL studies reveal that the faster component of the decay can be associated with the Shockley Read Hall (SRH)- nonradiative recombination which decreases with the increase in nitrogen concentration. The decay period corresponding to the slower component is attributed to the radiative recombination at the color centers.