Near-infrared photoluminescence properties of neodymium in in situ doped AlN grown using plasma-assisted molecular beam epitaxy

Fluorescence of Er^3+:AlN polycrystalline ceramic

“…It is tempting to attribute this multiplicity to the ceramic structure, since there must be many defect sites at the boundaries between grains, or to traces of other compounds too small to be detected in our x-ray diffraction measurements. However, spectroscopic evidence that rare earth dopants enter more than one type of site in a nitride host is not uncommon, often with one type of site dominant as we believe to be true in the present case [7,27,[36][37][38][39]. The dominant site for rare earths in AlN is often identified with substitution for Al [38,39], suggesting the possibility that one of the minority spectra is due to Er substituting for N. This multisite occupation is perhaps dependent on the techniques selected for crystal growth and doping, but is certainly not limited to ceramics [40].…”

“…The stimulated emission characteristics are more problematic, as the strongest transitions are rather near the zero line and even the longest wavelength lines are only about half as far from the zero line as in a host like YAG [43]. This is not unexpected, as the crystal field splitting in nitrides is often found to be small compared to that in most oxide hosts [7]. At cryogenic temperatures the longerwavelength stimulated emission peaks are stronger than at room temperature, and despite the small crystal field splitting the Boltzmann thermal population factors relating absorption to emission cross sections are adequately small.…”

“…One of the major challenges associated with rare-earth doped nitrides is the difficulty with which these cations can be uniformly incorporated into the host lattice. One can achieve reasonable concentrations of Nd 3+ , for example, by using molecular beam epitaxy, but only in thin films [6,7]. Other thin film methods include co-deposition of nitride and dopant through radio-frequency sputtering of a mixed metal target [8,9] and ion implantation into previously formed nitride films [10,11].…”

Ultrawide‐Bandgap Semiconductors: Research Opportunities and Challenges

“…In this case, it is critical to control inhomogeneous broadening of the dominant rare-earth dopant optical transition, which can be aided by substitutional doping using plasma-assisted MBE, for which it has been shown that the vast majority of Nd dopants (>95%) take the majority site. [273] Other possibilities for UWBG-semiconductor-based quantum information systems could involve valley-polarized electrons (i.e. "valleytronics") or superconductivity, both of which have been reported in diamond.…”

Photoluminescence of (BA0.96ND0.04) (TI0.96HO0.04) O3 Ceramic Under 638-Nm Excitation

“…The PL signals from Ho 3+ ions in BNTH4 were so intense that they concealed the traditional Raman spectra of BaTiO3. Upon 638-nm excitation, two PL bands of around 653 and 755 nm wavelength appeared in the spectrum of BNTH4 (Figure 3b), originating from 5 F5→ 5 I8 and 5 F4/ 5 S2→ 5 I7 transitions of Ho 3+ , respectively, as observed in Figure 3a; two additional PL bands at 804 and 875 nm correlated to PL of Nd 3+ (Figure 3b), which are attributed to 4 F5/2→ 4 I9/2 and 4 F3/2→ 4 I9/2 transitions of Nd 3+ [13,[17][18][19][20][21]. 638-nm laser line [18].…”