Manifestation of k‐linear term effects on the Zeeman splitting of the A1‐exciton emission lines in ZnO

Abstract

The magneto-luminescence spectra of the fourfold n = 1 A-exciton in ZnO up to H = 5 T are reported. The Zeeman splitting in the configuration H 11 c, k 1 c, E I c clearly demonstrat,es the influence of the k-linear energy terms allowed for the k-components perpendicular to the c-axis for 1', valence bands of the wurtzite structure. The appropriate exciton coupling matrix is calculated. From the comparison with the experimental results the A-valence band slope C = = 2 x 10 -10 eV cm is calculated.Die Magnet,olumineszenzspektren der vier n = 1 A-Exzitonenzustiinde in ZnO werden bis zu Magnetfeldern von 5 T untersucht. Die Zeeman-Aufspaltung fur die Geometrie H 11 c, k 1 c, E 1 c zeigt deutlich den EinfluB der k-linearen Energieterme fur die Komponenten des k-Vektors senkrecht zur c-Achse fur I',-Valenzbiinder von Wurtzit. Die zugehorige Exziton-Kopplungsmatrix wird berechnet. Der Vergleich mit den experimentellen Ergebnissen ergibt fur die Steigung des A-Valenzbandes C = 2 X 10-lo eV cm.

Valence-band-ordering of a strain-free bulk ZnO single crystal identified by four-wave-mixing spectroscopy technique

“…The excitons involved in the respective transitions are termed A-, B-, and C-excitons and abbreviated as X A , X B , and X C . Numerous reports have emerged over the past 50 years postulating either C 9 -symmetry [9][10][11][12][13][14][15][16][17][18] or C 7 -symmetry 1, [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] for the uppermost E 1 VB, as shown schematically on the right and left ends in Fig. 1(a), respectively.…”

Ground and Excited States of the Biexciton and the M‐Band Luminescence in Highly Excited ZnO

“…The discussion will essentially follow the classification 4.1 E,,, 1 c and 4.2 E,,, I I c. From [14] we deduce kf = 1.3 x lo6 em-1 for our experimental configuration.…”

“…Thus the transition to longitudinal and transverse r5 excitons is dipole-allowed. (Ar; and Ar; in our nonienclature correspond to Ix), and 1~)~ in [14].) Due to k-linear terms, there is a coupling between the r2 triplet exciton (Itr) in [14]) and the r'f polariton, so that the Ar, exciton mixes with the allowed r5 final state.…”

Excitonic Effects and Energy Upconversion in Bulk and Nanostructured ZnO

“…Γ 7 -Γ 9 -Γ 7 vs. Γ 9 -Γ 7 -Γ 7 , was long-debated in the literature [11][12][13][14][15][16][17][18][19][20][21]. Recent experimental and theoretical studies [11,20,21] have favored the Γ 7 symmetry of the topmost A subband, which is different from other wurtzite semiconductors like CdS and GaN.…”