Shape and size controlled lead sulfide quantum dots for optical refrigeration applications

Gurinder Kaur; M. S. Bakshi; Raman Kashyap

doi:10.1117/12.2078279

27 February 2015 Shape and size controlled lead sulfide quantum dots for optical refrigeration applications

Gurinder Kaur, M. S. Bakshi, Raman Kashyap

Proceedings Volume 9373, Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling XII; 93730M (2015) https://doi.org/10.1117/12.2078279
Event: SPIE OPTO, 2015, San Francisco, California, United States

Abstract

Lead sulfide (PbS) quantum dots are attractive candidates for optical refrigeration due to the tuneability of their band gap as a function of size and the resulting quantum confinement. We focus on the simple and straightforward method of synthesis of PbS NPs coated with zein protein with well-defined morphologies which show remarkable pH responsive behavior and excellent photo physical properties. The synthesis of PbS NPs in the presence of zein depicts a fine shape control effect as indicated in TEM images. At 0.4 %, zein produces nanocubes of ~ 42 nm which convert into spheres of almost equal dimensions with 0.2 % and 0.1 % zein. Since all reactions contain equal amount of precursor with identical conditions except the amount of zein, the shape transformation from nanocubes to spheres is mainly due to the decrease in the amount of zein from 0.4 to 0.2 %. The presence of protein coating makes the NPs bioactive and pH responsive. An increase in the pH systematically increases the absorbance of PbS NPs with a significant red shift which is simultaneously shown by remarkable color change in the solution from light grey with orange tinge to dark brown. These photo physical properties may have implications on laser cooling and it will be discussed.

Citation Download Citation

Gurinder Kaur, M. S. Bakshi, and Raman Kashyap "Shape and size controlled lead sulfide quantum dots for optical refrigeration applications", Proc. SPIE 9373, Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling XII, 93730M (27 February 2015); https://doi.org/10.1117/12.2078279

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