Crystal-field analysis and Zeeman splittings of energy levels of Nd3+ (4f3) in GaN

Abstract

The crystal-field splitting and Zeeman splitting of energy levels of Nd 3þ (4f 3) doped into semiconducting GaN (3.2 eV) grown in the hexagonal (huntite) phase by plasma-assisted molecular beam epitaxy have been modeled using a parameterized Hamiltonian defined to operate within the complete 4f 3 electronic configuration of Nd 3þ substituted for Ga 3þ in the lattice. Zeeman splittings were obtained by applying magnetic fields up to 6.6 T with the fields parallel and perpendicular to the crystallographic c-axis. The experimental energy (Stark) levels were obtained from a recent spectroscopic study on the same samples, where the combined excitation emission spectroscopy (CEES) identified the majority of Nd 3þ ions as replacing Ga 3þ in sites of C 3v symmetry. The manifolds of Nd 3þ (4f 3) 2Sþ1 L J modeled for the crystal-field splitting include the ground state, 4 I 9/2 , and excited states 4 I 11/2 , 4 I 13/2 , 4 F 3/2 , 4 F 5/2 , 2 H 9/2 , 4 F 7/2 , 4 S 3/2 , 4 G 5/2 , and 4 G 7/2. The energies of 41 experimental Stark levels from these manifolds were modeled through the use of a Monte Carlo method in which independent crystal-field parameters (CFP) were given random starting values and optimized using standard least-squares fitting between calculated and experimental Stark levels. Irreducible representations (irreps) and crystal field quantum numbers (l) were assigned to the energy level states of the 4 I 9/2 and 4 F 3/2 multiplet manifolds based on an analysis of the Zeeman data. This allows determination of which of the competing local minima should be considered to be the physically significant minimum. Using standard least-squares fitting between calculated and experimental Stark levels for Nd 3þ in C 3v symmetry, we obtain a final standard deviation of 7.01 cm À1 (rms ¼ 5.48 cm À1). V

Electronic structure analysis of rare earth ions Ce and Nd doped gallium nitride

“…[7][8][9][10][11][12][13][14] The synthesis of Nd doped GaN by plasma-assisted molecular beam epitaxy was reported by Readinger et al 15 Metcalfe et al studied the optical characterization of Nd 3þ emission spectra 16 and Gruber et al studied the stark levels of Nd doped GaN. 17 All these efforts along with further future investigations could lead to the further development of first pumped Nd doped GaN laser diode which will have highest laser efficiency because of pumping action. The location and hybridization of RE dopants within valance band (VB) and conduction band (CB) of host greatly influence the emission and luminescence and also may give rise to the magnetic exchange interactions.…”

Covalent bonding andJ–Jmixing effects on the EPR parameters of Er3 +ions in GaN crystal

“…In recent years much attention has been paid to the investigation of rare-earth (RE) doped GaN semiconductors, due to their potential in micro-and optoelectronics devices applications. [1][2][3][4][5][6][7][8][9][10][11] Of particular interest has been the electrical and optical properties of trivalent Er 3+ in GaN host, [5][6][7][8][9][10][11] since the 1.54 µm luminescence center arising from the 4 I 13/2 → 4 I 15/2 transition is in the region of minimal loss in optical fibers.…”

Achieving Effective Multimodal Imaging with Rare-Earth Ion-Doped CaF2 Nanoparticles

“…Based on the results of previous studies [61,62], we tested the emission spectra of CaF 2 :Y,Gd,Nd NPs in the range of 900-1500 nm using an 808 nm laser as the excitation light source, as shown in Figure 3a. The main emission peaks of our NPs were at 1050 nm and 1330 nm, which correspond to the electron transition of Nd 3+ from the excited state 4 F 3/2 energy level to 4 I 11/2 , and 4 I 13/2 levels, respectively [63,64]. Meanwhile, the increase in laser power significantly increased the NIR-II luminescence intensity of Nd 3+ (Figure 3b).…”