Measurement of the optical band gap and crystal-field splitting in wurtzite CdTe.

Pierre Lefebvre (1) , Tristan Richard (1) , Jacques Allègre (1) , Henry Mathieu (1) , Anne Combette-Roos (2) , William Granier (2)

1 GES - Groupe d'étude des semiconducteurs
2 LPCMS - Laboratoire de Physicochimie des Matériaux Solides

CdTe nanocrystals embedded in a sodium borosilicate matrix, obtained by a sol-gel process, present a wurtzite (hexagonal) structure. Low-temperature photoluminescence and absorption spectra are measured for samples containing bulklike nanocrystals large enough to suppress confinement effects. Thus, the fundamental free-exciton gap and the splitting between the A (Γv9-Γc7) and B (Γv7-Γc7) excitons of bulk wurtzite CdTe are measured. We find EAg=1653±1 meV and EAg-EBg=46.5±1.0 meV, which corresponds to a crystal-field splitting Δcr=71.6±1.5 meV.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Optique [physics.optics]; Micro et nanotechnologies/Microélectronique; Optique / photonique

Pierre Lefebvre, Tristan Richard, Jacques Allègre, Henry Mathieu, Anne Combette-Roos, et al.. Measurement of the optical band gap and crystal-field splitting in wurtzite CdTe.. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 1996, 53 (23), pp.15440. ⟨10.1103/PhysRevB.53.15440⟩. ⟨hal-01179205⟩