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Published online: 15 April 2009 | doi:10.1038/nchina.2009.76

Optoelectronic materials: Into the blue

Tim Reid

Original article citation

Yan, D. P. et al. Ordered poly(-phenylene)/layered double hydroxide ultrathin films with blue luminescence by layer-by-layer assembly. Angew. Chem. Int. Ed. doi:10.1002/anie.200900178 (2009).

Introduction

© (2009) Wiley Interscience

Organic compounds called -conjugated polymers show excellent optoelectronic properties for devices such as liquid crystal displays, light-emitting diodes or solar cells. Jun Lu and Min Wei at Beijing University of Chemical Technology and co-workers¹ have now combined -conjugated polymers in a rigid matrix to create ultrathin films that emit strong blue luminescence.

-conjugated polymers have rod-shaped structures that can be aligned into thin films to provide a useful polarizing effect. The films are unstable under changes in temperature or radiation, however, and may partly break down into molecular aggregates that cause signals to be red-shifted. This makes it difficult to obtain blue light emission.

The researchers avoided this problem by building an ultrathin film containing alternate layers of a -conjugated polymer called APPP and a rigid, crystalline, layered double hydroxide. The films gave off uniform bright blue luminescence when irradiated with ultraviolet light (pictured), and remained stable for much longer than pure APPP films.

The rigid hydroxide layers suppress destructive vibrations in the APPP polymer, and contain quantum energy wells that confine the APPP valence electrons. The optoelectronic properties of the films could be tuned by varying the alignment and ingredients of the different layers, for a variety of applications.

The authors of this work are from:
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, China; School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry, Ministry of Education, Nanjing University, Nanjing, China.

Reference

1. Yan, D. P. et al. Ordered poly(-phenylene)/layered double hydroxide ultrathin films with blue luminescence by layer-by-layer assembly. Angew. Chem. Int. Ed. doi:10.1002/anie.200900178 (2009). | Article |