Photocurrent study of beta-ray priming in CVD diamond

• Published in: Diamond and related materials Vol. 13; no. 4; pp. 914 - 917
• Main Authors: Manfredotti, C., Fizzotti, F., Vittone, E., Paolini, C., Olivero, P., Lo Giudice, A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2004; Elsevier
• Subjects: Below-gap photocurrent (BGPC); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; CVD diamond; Dosimetry; Electronic transport in condensed matter; Exact sciences and technology; Growth from vapor; Materials science; Methods of crystal growth; physics of crystal growth; Persistent photocurrent (PPC); Photoconduction and photovoltaic effects; Photoconduction and photovoltaic effects; photodielectric effects; Physics; Priming; Persistent photocurrent (PPC); Priming; Dosimetry; CVD diamond; Below-gap photocurrent (BGPC); Inorganic compounds; Beta-rays; Physical radiation effects; Diamonds; Photocurrents; Crystal growth from vapors; Experimental study; CVD
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2003.10.083

Priming by X-rays or by beta-rays is generally needed in order to qualify CVD diamond for nuclear detection or for dosimetry. The priming effect is usually attributed in filling the hole traps, which are responsible for the charge collection efficiency of the detector. Emptying the filled traps can be easily detected by Thermoluminescence (TL), which is considered to be a measure of the absorbed dose. In this work, we prove that below-gap photocurrent (BGPC) can also be used in the same way and it is dominated by the optical detrapping of holes from the same centers. Time dependence of this beta-rays induced persistent photocurrent (PPC), which in fact, depends only on the total number of photons impinging onto the sample. In fact, at long times or for large number of photons, the photocurrent approaches to the same limit of PC for a null dose. The hole trapping centers distribution seems to extend from 1.25 to 2.5 eV valence band.