Photoluminescence spectra from the high-Tc superconductor YBa2Cu3O7−x, the semiconductor GaAs, and GaP under intense picosecond laser excitation were studied with their surfaces exposed to different alkali solutions. Strong absorption of D lines of neutral-alkali atoms was observed in these spectra. These absorption lines indicate that free ground-state alkali atoms were formed by recombination of the sublimated alkali ions with photoelectrons through various processes.
© 1989 Optical Society of America
Original Manuscript: January 23, 1989
Manuscript Accepted: May 3, 1989
Published: July 15, 1989
K. M. Yoo and R. R. Alfano, "Alkali D-line absorption in the luminescence spectrum of solid–fluid interfaces under high-intensity laser excitation," Opt. Lett. 14, 725-727 (1989)