SearcharxivSearch

arXiv subjects

A. Crnjac

Publications and source records attributed to A. Crnjac.

3 recordsLinked to original sources

Depletion depth measurements of new large area silicon carbide detectors

The ion beam induced charge technique with proton microprobe is used to characterise newly developed p-n junction large area silicon carbide detectors. They were recently produced as part of the ongoing program to develop a new particle identification wall for the focal plane detector of the MAGNEX magnetic spectrometer at INFN - Laboratori Nazionali del Sud in view of the NUMEN experimental campaigns. Four silicon carbide devices are studied. Proton beams over a 1.26 to 6.00 MeV incident energy range are used to probe the active area and the depletion depth of each device. The energy loss tables for the silicon carbide material are checked, finding an empirical correction that is then used to quantify the depletion depth at the full depletion voltage through energy loss measurements of 3.40 MeV proton beams irradiating the back side of the devices. It is possible to fully deplete the devices provided that the epitaxial layer is grown properly on the substrate.

physics.ins-det

Efficient fabrication of high-density ensembles of color centers via ion implantation on a hot diamond substrate

Nitrogen-Vacancy (NV) centers in diamond are promising systems for quantum technologies, including quantum metrology and sensing. A promising strategy for the achievement of high sensitivity to external fields relies on the exploitation of large ensembles of NV centers, whose fabrication by ion implantation is upper limited by the amount of radiation damage introduced in the diamond lattice. In this works we demonstrate an approach to increase the density of NV centers upon the high-fluence implantation of MeV N2+ ions on a hot target substrate (>550 °C). Our results show that, with respect to room-temperature implantation, the high-temperature process increases the vacancy density threshold required for the irreversible conversion of diamond to a graphitic phase, thus enabling to achieve higher density ensembles. Furthermore, the formation efficiency of color centers was investigated on diamond substrates implanted at varying temperatures with MeV N2+ and Mg+ ions revealing that the formation efficiency of both NV centers and magnesium-vacancy (MgV) centers increases with the implantation temperature.

cond-mat.mtrl-sci

Fluorine-based color centers in diamond

We report on the creation and characterization of the luminescence properties of high-purity diamond substrates upon F ion implantation and subsequent thermal annealing. Their room-temperature photoluminescence emission consists of a weak emission line at 558 nm and of intense bands in the 600 - 750 nm spectral range. Characterization at liquid He temperature reveals the presence of a structured set of lines in the 600 - 670 nm spectral range. We discuss the dependence of the emission properties of F-related optical centers on different experimental parameters such as the operating temperature and the excitation wavelength. The correlation of the emission intensity with F implantation fluence, and the exclusive observation of the afore-mentioned spectral features in F-implanted and annealed samples provides a strong indication that the observed emission features are related to a stable F-containing defective complex in the diamond lattice.

cond-mat.mtrl-sci