Photoconductive gain in single crystal diamond detectors
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2021-03-25 |
| Journal | Journal of Applied Physics |
| Authors | Theodor GrĆ¼nwald, M. Schreck |
| Institutions | University of Augsburg |
| Citations | 6 |
Abstract
Section titled āAbstractāDiamond crystals equipped with two metal electrodes can be operated as solid state ionization chambers for the detection of energetic radiation. Under irradiation with single Ī± particles, the generated free electrons and holes are collected with a maximum efficiency close to 100%. When the same detectors are used for dosimetry in high intensity and high energy photon or particle beams, photoconductive gain G with values up to ā106 is frequently observed as described in the literature. In this work, we studied theoretically the irradiation induced conductivity of perfect diamond single crystals with ohmic contacts containing nitrogen and boron with concentrations NN and NB, respectively, as only chemical impurities. Based on four rate equations, two considering the charge states of N and B and two the concentrations of free carriers n and p, and, additionally, the neutrality condition, we could derive analytical solutions for the gain G as a function of impurity concentrations, crystal thickness, and excitation density. It turned out that G varies systematically with the compensation ratio R=(NNāNB)/NB over five orders of magnitude. For Rā103, the gain G is close to unity. With decreasing R, the gain increases ā1/R until saturation is reached for RāŖ1 and Gā104-105. Our theoretical data yield plausible explanations for the major trends that have been found experimentally in previous studies. They provide a valuable guideline for the future synthesis of diamond crystals to be used for manufacturing UV and radiation detectors.
Tech Support
Section titled āTech SupportāOriginal Source
Section titled āOriginal SourceāReferences
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