Measuring the anti-Stokes luminescence of CdSe/ZnS quantum dots for laser cooling applications

Ross S. Fontenot; Veerendra K. Mathur; John H. Barkyoumb; Carl E. Mungan; Thanh N. Tran

doi:10.1117/12.2222826

17 May 2016 Measuring the anti-Stokes luminescence of CdSe/ZnS quantum dots for laser cooling applications

Ross S. Fontenot, Veerendra K. Mathur, John H. Barkyoumb, Carl E. Mungan, Thanh N. Tran

Proceedings Volume 9821, Tri-Technology Device Refrigeration (TTDR); 982103 (2016) https://doi.org/10.1117/12.2222826
Event: SPIE Defense + Security, 2016, Baltimore, MD, United States

Abstract

The first demonstration of laser cooling of solids was of an ytterbium doped fluorozirconate glass. While this groundbreaking work successfully showed that it is possible to cool solids using laser cooling, rare-earth materials are governed by Boltzmann statistics limiting their cooling ability to about 100 K. Direct-bandgap semiconductors, on the other hand, are governed by Fermi-Dirac statistics, which allows for a theoretical cooling limit of 10 K as well as higher cooling efficiencies. Recently, it was demonstrated that it is possible to cool CdS nanoribbons by 40 K. That success was attributed to CdS strong electron-phonon coupling, which makes it possible to resonantly annihilate more than one longitudinal optical phonon during each up conversion cycle. To further increase the cooling power, large external quantum efficiency is required. A nanostructure is preferred because it creates confined excitons of tunable wavelength and reduces the self-absorption of the anti-Stokes fluorescence owing to the shorter path length for photons to escape the crystal. However, organically passivated quantum dots have a low quantum yield due to surface related trap states. A core-shell nanostructure alleviates this problem by passivating the surface trap states and protecting against environmental changes and photo-oxidative degradation. As such, we chose to investigate CdSe/ZnS core shell structure for laser cooling applications. This article highlights the measurement of the anti-Stokes luminescence, the dependence of the laser wavelength on the anti-Stokes emission of colloidal quantum dots, and the successful incorporation of CdSe/ZnS into polymers.

Citation Download Citation

Ross S. Fontenot, Veerendra K. Mathur, John H. Barkyoumb, Carl E. Mungan, and Thanh N. Tran "Measuring the anti-Stokes luminescence of CdSe/ZnS quantum dots for laser cooling applications", Proc. SPIE 9821, Tri-Technology Device Refrigeration (TTDR), 982103 (17 May 2016); https://doi.org/10.1117/12.2222826

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available