Dr. Brian K. Crone Profile

Dr. Brian K. Crone

at Los Alamos National Lab

SPIE Involvement:

Author

Publications (2)

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 | 26 August 2008 Paper

Interdigitated photoconductors using organic and small molecule materials

A. Niemeyer, I. Campbell, F. So, B. Crone

Proceedings Volume 7052, 70520O (2008) https://doi.org/10.1117/12.793876

KEYWORDS: Quantum efficiency, Excitons, Electrodes, Diffusion, Interfaces, Heterojunctions, Photoresistors, Absorption, Data modeling, Molecules

Read Abstract +

In this study we present research results on interdigitated organic / small molecule photoconductors. We investigated photoconductivity in interdigitated lateral photoconductors with aluminum contacts, using (1) a spin-coated organic blend and (2) evaporated organic multilayers as the active layer. The spin-coated devices were made with a blend of a poly[2-methoxy-5-(2-ethylhexyl-oxy)-1,4-phenylene-vinylene] [MEH-PPV] and {6}-1-(3-(methoxycarbonyl) propyl)-{5}-1-phenyl-[6,6]-C61 [PCBM]. In spin-cast devices, the quantum efficiency was limited by the dissociation of the excitons. The field dependence of the dissociation of the excitons was explained using a modified Onsager model for charge dissociation. The evaporated devices were made from layers of alpha-sexithiophene [α-6T] and C60. In the evaporate devices, trap sites in the active layer limited the quantum efficiency. By modeling the quantum efficiency based on exciton diffusion to the interface and the dissociation of the excitons, the experimental quantum efficiency was explained by a trapping model with a charge carrier lifetime of 0.002s.

Proceedings Article | 16 October 2007 Paper

The role of isoelectronic dopants in organic light emitting diodes

B. Crone, I. Campbell, D. Smith

Proceedings Volume 6655, 665519 (2007) https://doi.org/10.1117/12.732079

KEYWORDS: Electrons, Diodes, Quantum efficiency, Organic light emitting diodes, Molecules, Copper, Electroluminescence, Polymers, Electrodes, Calcium

Read Abstract +

Power efficiency is an important parameter for all OLEDs, and is particularly critical for lighting applications. To maximize the power efficiency one must optimize charge injection, carrier transport, and radiative quantum efficiency, while minimizing energy losses. In this work we discuss how isoelectronic dopants can be used to address these problems. It can be difficult to produce efficient electrical contacts, particularly to large energy gap organic materials, and thus the contacts often limit the performance and stability of OLEDs . Recent results by several groups have attributed improved hole injection in poly (9,9' dioctylfluorene) [PFO] based LEDs to charge trapping, but the origin of the traps is unknown. In order to understand the role of traps in improving injection we studied poly[2-methoxy, 5-(2'- ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) devices with C₆₀ molecules at the anode to improve hole injection. Isoelectronic dopants are used widely as recombination centers in organic light emitting diodes (OLEDs). In these systems one wants to maximize quantum efficiency by effectively trapping charges on the emitting dopants, while at the same time maximizing power efficiency by maintaining good charge transport. An understanding of the influence of the depth of the dopant on charge capture, and charge transport will aid in optimizing doped organic LEDs. We have looked at the OLED system consisting of the polymer PFO, and the organometallic molecule PhqIr. We show that PhqIr acts as a shallow hole trap in PFO, and that the charge transport and luminescence properties of this system are described by quasi-equilibrium statistics.

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