Temperature dependence of the fundamental excitonic resonance in lead-salt quantum dots

Journal Reference

Appl. Phys. Lett. 107, 022106 (2015)

Fangyu Yue^1,2, Jens W. Tomm²,Detlef Kruschke³, Bruno Ullrich⁴ Junhao Chu^1,5

[expand title=”Show Affiliations”]

1. Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, 500 Dongchuan Rd, Shanghai 200241, China
2.  Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Str. 2A, 12489 Berlin, Germany
3. Institut für Angewandte Photonik e.V. Rudower Chaussee 29/31, 12489 Berlin, Germany
4. Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico and Ullrich Photoincs LLC, Wayne, Ohio 43466, USA
5. National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, 500 Yutian Rd, Shanghai 200083, China

[/expand]

Abstract

The temperature dependences of the fundamental excitonic resonance in PbS and PbSe quantum dots fabricated by various technologies are experimentally determined. Above ∼150 K, sub-linearities of the temperature shifts and half widths are observed. This behavior is analyzed within the existing standard models. Concordant modeling, however, becomes possible only within the frame of a three-level system that takes into account both bright and dark excitonic states as well as phonon-assisted carrier redistribution between these states. Our results show that luminescence characterization of lead-salt quantum dots necessarily requires both low temperatures and excitation densities in order to provide reliable ensemble parameters.

© 2015 AIP Publishing LLC

Go To Appl. Phys.