Ultrafast energy transfer of silver ultrafine particles in aqueous solutions as investigated by the ultrafast lensing effect technique

Ultrafast relaxation dynamics of silver ultrafine particles in aqueous solu tions was measured by an ultrafast lensing effect (ULE) method using two ty pes of samples with SDS (sodium dodecyl sulfate) and without SDS. The fit t o the ULE time evolution required three exponential components: one for the increase and two others for the decrease. The time constants were estimate d as 1, 3, 7 ps for the sample without SDS and as I, 2, and 23 ps for the s ample with SDS. The ultrafast relaxation dynamics was discussed in connecti on with the behavior of photoexcited electrons. (C) 2000 Elsevier Science B .V. All rights reserved.