Photoluminescence and lasing of thin CdS films on glass formed by pulsed-laser-deposition

The photoluminescence of thin film CdS on glass grown by pulsed laser depos ition is presented in the temperature range 4-300 K. The radiative recombin ation at the fundamental transition refers to band-to-band transitions lead ing to a peak centered at 2.48 eV at 300 K. A peak at such a high energy is not observed with single crystals and thin films formed by different techn iques showing peaks at 2.42 and around 2.21 eV. In addition, optically pump ed laser action at 248 eV at 300 K is demonstrated. The feedback is provide d by self-formed microcavities within the hexagonal lattice of the samples. (C) 2000 Elsevier Science B.V. All rights reserved.