Nanocrystal sensitized photovoltaics and photodetectors with performance enhanced using ligand engineering

David M. Schut; George M. Williams Jr.; Stefan Arteaga; Thomas L. Allen; Thomas Novet

doi:10.1117/12.887753

17 May 2011 Nanocrystal sensitized photovoltaics and photodetectors with performance enhanced using ligand engineering

David M. Schut, George M. Williams Jr., Stefan Arteaga, Thomas L. Allen, Thomas Novet

Proceedings Volume 8035, Energy Harvesting and Storage: Materials, Devices, and Applications II; 80351B (2011) https://doi.org/10.1117/12.887753
Event: SPIE Defense, Security, and Sensing, 2011, Orlando, Florida, United States

Abstract

Nanocrystal quantum dot photovoltaics and photodetectors with performance optimized by engineering the nanocrystals size and the optoelectronic properties of the nanocrystal's chemical coating are reported. Due to the large surface-to-volume ratio inherent to nanocrystals, the surface effects of ligands used to chemically coat and passivate nanocrystals play a significant role in device performance. However, the optoelectronic properties of ligands are difficult to ascertain, as the band structure of the ligand-capped nanoparticle system is complex and difficult to model. Using density-of-states measurements, we demonstrate that modeling of electropositive and electronegative substituents and use of the Hammett equation, are useful tools in optimizing nanocrystal detector performance. A new particle, the Janus-II nanoparticles, developed using 'charge-donating' and 'charge-withdrawing' ligands distributed over opposite surfaces of the nanocrystal, is described. The polarizing ligands of the Janus-II nanoparticle form a degeneracy-splitting dipole, which reduces the overlap integral between excitonic states, and thus reduces the probability of carrier recombination, allowing carrier extraction to take place more efficiently. This is shown to allow increased photodetection efficiencies and to allow the capture of multiple exciton events in working photodetectors.

Citation Download Citation

David M. Schut, George M. Williams Jr., Stefan Arteaga, Thomas L. Allen, and Thomas Novet "Nanocrystal sensitized photovoltaics and photodetectors with performance enhanced using ligand engineering", Proc. SPIE 8035, Energy Harvesting and Storage: Materials, Devices, and Applications II, 80351B (17 May 2011); https://doi.org/10.1117/12.887753

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