Abstract
We study the emission properties of close-packed films of PbS nanocrystals that show emission in the infrared. In time resolved photoluminescence measurements, we observe a fast decay time of and a slow component between 20 and , depending on the temperature, which are attributed to decay from core and surface states, respectively. Photoluminescence excitation and temperature-dependent photoluminescence measurements show that these states are coupled by thermal activation and energy transfer. These transfer processes efficiently replenish the core states with charge carriers from the surface states, increasing the photoluminescence yield.
- Received 23 August 2007
DOI:https://doi.org/10.1103/PhysRevB.77.085322
©2008 American Physical Society