Light-emitting structures based on nanocrystalline (Si/CaF2) multiquantum wells

Periodic nanocrystalline (Si/CaF2) multilayers, deposited on (111) silicon by Molecular Beam Epitaxy (MBE) at room temperature, were used to fabricate simple light emitting structures and to study their electrical and optoele ctronic properties. Photoluminescence (PL) and electroluminescence (EL) spe ctra from the same area of the devices are approximately the same, indicati ve of the same emission mechanism. Current-voltage characteristics reveal i mportant phenomena in vertical carrier transport. Regions of negative diffe rential resistance and current oscillations were observed and were tentativ ely attributed to resonant tunneling at high electric fields under field do main formation. (C) 1999 Published by Elsevier Science B.V. All rights rese rved.