Ion beam characterization of advanced luminescent materials for application in radiation effects microscopy

Abstract

The ion photon emission microscope (IPEM) is a technique developed at Sandia National laboratories (SNL) to study radiation effects in integrated circuits with high energy, heavy ions, such as those produced by the 88" cyclotron at Lawrence Berkeley National Laboratory (LBNL). In this method, an ion-luminescent film is used to produce photons from the point of ion impact. The photons emitted due to an ion impact are imaged on a position-sensitive detector to determine the location of a single event effect (SEE). Due to stringent resolution, intensity, wavelength, decay time, and radiation tolerance demands, an engineered material with very specific properties is required to act as the luminescent film. The requirements for this material are extensive. It must produce a high enough induced luminescent intensity so at least one photon is detected per ion hit. The emission wavelength must match the sensitivity of the detector used, and the luminescent decay time must be short enough to limit accidental coincidences. In addition, the material must be easy to handle and its luminescent properties must be tolerant to radiation damage. Materials studied for this application include plastic scintillators. GaN and GaN/InGaN quantum well structures, and lanthanide-activated ceramic phosphors. Results from characterization studies on these materials will be presented; including photoluminescence, cathodoluminescence, ion beam induced luminescence, luminescent decay times, and radiation damage. Results indicate that the ceramic phosphors are currently proving to be the ideal material for IPEM investigations

Thermal Stability and Radiation Tolerance of Lanthanide-Doped Cerium Oxide Nanocubes

“…Although well above the operating temperature of many applications, this temperature regime shows that no significant nanoscale-enhanced sintering is observed in these systems. The poor irradiation stability observed in this work is similar to that seen in crystalline tungstate nanoparticles irradiated with heavy ions [23,24]. This in stark contrast to other amorphous ceramic nanoparticles and core@shell nanoparticles that have been explored, which suggests that the amorphous phase may be extremely important for radiation stability [25,26].…”

InGaN/GaN multiple quantum well for fast scintillation application: radioluminescence and photoluminescence study

“…The luminescence spectra and decay kinetics of an InGaN/GaN MQW structure were investigated using UV and soft x-ray excitations [11]. The used excitation wavelength 325, 339 and 375 nm were chosen to generate carriers in GaN layers (325 nm and 339 nm) or in the InGaN QWs, only (375 nm).…”

In situ luminescence measurements of GaN/Al2O3 film under different energy proton irradiations

“…[21][22][23][24][25] Branson et al conducted a study on the luminescence of In-GaN/GaN using IBIL, PL and cathodeluminescence measurement methods, and found that luminescence intensity depends on the specific excitation method employed in each measure-ment technique. [18] In this study, IBIL spectra of GaN/Al 2 O 3 at various depths were acquired by adjusting the incident ion energy to adapt to different film thicknesses. Subsequently, we conducted an in-depth analysis of the evolution of luminescence observed in GaN/Al 2 O 3 during irradiation.…”