作者: Augustinas Galeckas , Vytautas Grivickas , Jan Linnros , Vitalijus Bikbajevas
DOI:
关键词: Exciton 、 Phonon 、 Direct and indirect band gaps 、 Materials science 、 Absorption (electromagnetic radiation) 、 Brillouin zone 、 Absorption spectroscopy 、 Molecular physics 、 Emission spectrum 、 Doping
摘要: The momentum conserving indirect excitonic transitions from the valence band maximum to conduction minima close X1 points in Brillouin zone have been investigated for moderately doped n-type GaP using a novel depthand time-resolved excess free-carrier-absorption (FCA) technique. Different singularities due band-to-band and absorption are observed near gap edge at 77 K. Observations clearly yield signatures sharp no-phonon lines of excitons bound neutral sulfur (S) isoelectronic nitrogen (N) impurities, their complexes phonon replicas. A parallel investigation also reveals emission exciton S N as well sidebands. characteristic energies obtained our experiments compared with those reported literature. Optical nonlinearity principle line is observed.