Dr. Frederic S. Diana Profile

Dr. Frederic S. Diana

SPIE Involvement:

Author

Publications (1)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 18 August 2005 Paper

Time-resolved studies of fluorescence and band-edge charge carrier dynamics in In1-xGaxP colloidal quantum dots

Alexander Mikhailovsky, Frederic Diana, Sangcheol Kim, Edward Kramer, Pierre Petroff, Jeffrey Gerbec, Geoffrey Strouse

Proceedings Volume 5929, 59290R (2005) https://doi.org/10.1117/12.616419

KEYWORDS: Indium gallium phosphide, Luminescence, Nanoparticles, Gallium, Absorption, Picosecond phenomena, Carrier dynamics, Quantum dots, Electrons, Spectroscopy

Read Abstract +

In this submission, we report on the results of spectroscopic studies of charge carrier dynamics in colloidal In_1-xGa_xP quantum dots (QDs) with low levels of Ga doping (x~1%). These QDs exhibit large global Stokes shift of fluorescence (up to 300 meV) along with high emission yield (up to 30% in solution and 25% in films under blue excitation at 300 K) after post-synthesis photo-chemical treatment. In order to reveal the nature of large fluorescence Stokes shift and study the band-edge carriers dynamics, we performed time-resolved measurements of emission and photo-induced absorption changes in QDs with different sizes and surface passivation. The work was focused on the studies of differences between QDs subjected to photochemical surface passivation and bare nanoparticles. Time-resolved absorption spectroscopy indicates that holes' trapping strongly depends on passivation of surface trap states and can even suppress Auger multiparticle recombination in poorly passivated nanoparticles. Transient fluorescence measurements in well-passivated nanoparticles demonstrate that at short delays (<2 ns), emission Stokes shift is almost twice smaller than in steady-state measurements and matches the emission band in unpassivated QDs. At longer delays, time-resolved emission matches the spectra obtained with continuous wave (CW) excitation. We propose that initially photoluminescence occurs from quantum-confined state and subsequent hole relaxation onto surface/interface sites gives rise to emission with large global Stokes shift. In poorly passivated QDs, holes escape quickly to deep-trap states that leads to formation of low-efficiency broad emission band red-shifted with respect to the excitonic PL band.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

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

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years