Journal of Alloys and Compounds 581 (2013) 632–635
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Design and development of low-power driven hybrid electroluminescent lamp from carbon nanotube embedded phosphor material Deepika Yadav, Savvi Mishra, Virendra Shanker, D. Haranath ⇑ CSIR-National Physical Laboratory, Dr. KS Krishnan Road, New Delhi 110 012, India
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Article history: Received 7 May 2013 Accepted 19 July 2013 Available online 30 July 2013 Keywords: Electroluminescence Phosphor Carbon nanotube Hybrid material Electro-optical studies
a b s t r a c t We present a novel methodology to design a hybrid electroluminescent (EL) lamp by embedding carbon nanotubes (CNTs) inside the ZnS:Mn phosphor particles by conventional solid state diffusion technique. By doing so, the phosphor particles exhibited increase in EL brightness and efficiency at low operating voltages (1000 VAC), large area fabrication and economical feasibility limits its commercial use [6–8]. Hence, the AC driven powder EL lamps gain attention over their thin film counterparts. Moreover, to address the problems mentioned above and establish facile method of making large area devices, researchers have been working on variety of systems including organic/ inorganic hybrids but failed to some extent due to instability issues of organic materials at various operating conditions [9]. In the recent years, few reports appeared on enhanced EL at reduced threshold and operating voltages when CNTs are used as a field enhancer before the phosphor layer [10,11]. This concept ⇑ Corresponding author. Tel.: +91 11 4560 9385; fax: +91 11 4560 9310. E-mail address:
[email protected] (D. Haranath). 0925-8388/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jallcom.2013.07.124
worked partially well in terms of improving the lifetimes of the EL lamps but the operating voltages were still above >250 V [10]. Motivated by this work, we have modified the concept by deliberately embedding the CNTs into the phosphor particles by flux assisted solid state diffusion technique [12]. By doing so, we could design and develop a novel hybrid system and thereafter an EL lamp, which operates at significantly low voltages (
