Graham Turnbull

Dr. Graham Turnbull


Research Focus & Metrics

Academic Career Length

31Years (1996-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 March 2007 in Chemical Reviews
Verified
Journal Article
Closed access
ISIfor Samuel
Ifor Samuel
GTGraham Turnbull
Graham Turnbull

1 June 1996 in Optics Communications
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Journal Article
Closed access
GTGraham Turnbull
Graham Turnbull
DRD.A. Robertson
D.A. Robertson
GSG.M. Smith
G.M. Smith
LAL. Allen
L. Allen
MPMiles J. Padgett
Miles J. Padgett

1 October 2009 in Nature Photonics
Verified
Journal Article
Closed access
ISIfor Samuel
Ifor Samuel
ENEbinazar B. Namdas
Ebinazar B. Namdas
GTGraham Turnbull
Graham Turnbull

21 April 2008 in Applied Physics Letters
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Journal Article
Closed access
YYY. Yang
Y. Yang
GTGraham Turnbull
Graham Turnbull
ISIfor Samuel
Ifor Samuel
We demonstrate indirect electrically pumped lasing in a hybrid polymer laser. The lasers comprise a corrugated fluorene copolymer waveguide on an InGaN light-emitting diode and were driven under nanosecond pulsed operation. We observe the onset of distributed feedback lasing at 568nm for peak drive currents above 144A. Angle-resolved photoluminescence measurements identify the lasing mechanism as band edge feedback from a photonic stopband in the TE0 waveguide mode.

29 January 2004 in Advanced Functional Materials
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Journal Article
Closed access
PDF file
GHG. Heliotis
G. Heliotis
RXR. Xia
R. Xia
GTGraham Turnbull
Graham Turnbull
PAP. Andrew
P. Andrew
WBW. L. Barnes
W. L. Barnes
DBDonal Bradley
Donal Bradley

27 September 2023 in Nature
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Journal Article
Open access
PDF file
KYKou Yoshida
Kou Yoshida
JGJunyi Gong
Junyi Gong
AKAlexander L. Kanibolotsky
Alexander L. Kanibolotsky
PSPeter Skabara
Peter Skabara
GTGraham Turnbull
Graham Turnbull
ISIfor Samuel
Ifor Samuel
Organic semiconductors are carbon-based materials that combine optoelectronic properties with simple fabrication and the scope for tuning by changing their chemical structure1–3. They have been successfully used to make organic light-emitting diodes2,4,5 (OLEDs, now widely found in mobile phone displays and televisions), solar cells1, transistors6 and sensors7. However, making electrically driven organic semiconductor lasers is very challenging8,9. It is difficult because organic semiconductors typically support only low current densities, suffer substantial absorption from injected charges and triplets, and have additional losses due to contacts10,11. In short, injecting charges into the gain medium leads to intolerable losses. Here we take an alternative approach in which charge injection and lasing are spatially separated, thereby greatly reducing losses. We achieve this by developing an integrated device structure that efficiently couples an OLED, with exceptionally high internal-light generation, with a polymer distributed feedback laser. Under the electrical driving of the integrated structure, we observe a threshold in light output versus drive current, with a narrow emission spectrum and the formation of a beam above the threshold. These observations confirm lasing. Our results provide an organic electronic device that has not been previously demonstrated, and show that indirect electrical pumping by an OLED is a very effective way of realizing an electrically driven organic semiconductor laser. This provides an approach to visible lasers that could see applications in spectroscopy, metrology and sensing.