White Polymer Light‐Emitting Devices for Solid‐State Lighting: Materials, Devices, and Recent Progress

Abstract

White polymer light-emitting devices (WPLEDs) have become a field of immense interest in both scientific and industrial communities. They have unique advantages such as low cost, light weight, ease of device fabrication, and large area manufacturing. Applications of WPLEDs for solid-state lighting are of special interest because about 20% of the generated electricity on the earth is consumed by lighting. To date, incandescent light bulbs (with a typical power efficiency of 12-17 lm W(-1) ) and fluorescent lamps (about 40-70 lm W(-1) ) are the most widely used lighting sources. However, incandescent light bulbs convert 90% of their consumed power into heat while fluorescent lamps contain a small but significant amount of toxic mercury in the tube, which complicates an environmentally friendly disposal. Remarkably, the device performances of WPLEDs have recently been demonstrated to be as efficient as those of fluorescent lamps. Here, we summarize the recent advances in WPLEDs with special attention paid to the design of novel luminescent dopants and device structures. Such advancements minimize the gap (for both efficiency and stability) from other lighting sources such as fluorescent lamps, light-emitting diodes based on inorganic semiconductors, and vacuum-deposited small-molecular devices, thus rendering WPLEDs equally competitive as these counterparts currently in use for illumination purposes.

A luminescent mesoporous zirconium complex and it as a precursor of environmentally benign catalysts

“…The attracting feature of this route to white-light emission comes from the singlephased and single-doped phosphors that can be prepared through a low-cost chemical synthesis approach from zirconyl chloride, acetic acid, and ammonium persulfate at a temperature as low as 210 C without incurring the burden of intrinsic toxicity and without the need for stringent, intricate, tedious, or costly preparation steps. It is, however, obvious that crystalline MOFs or whitelight-emitting polymers are synthetically challenging, and environmental issues should also be evaluated due to use of large amount of environment-friendlyless organic solvents [23]. To the best of our knowledge, this is the first time we are reporting this amorphous organic complex as a potential candidate for singlephased and single-doped white-lighteemitting phosphor.…”

New electroluminescent carbazole-containing conjugated polymer: Synthesis, photophysics, and electroluminescence

“…EL enhancements up to two order magnitude were demonstrated [19,23e26]. Carbazole-containing polymers are reported as hosts in efficient electrophospohorescent LEDs [30]. Therefore possible use of new PCzE-PPV as a host in such LEDs is also interesting.…”

Organic emitters for solid state lighting

“…White electroluminescence from organic materials can be pursued by various approaches mainly classified into two categories [2,9]. The first one involves the combination of two or more emitters of different colors that can be (1) confined in different stacked layers or (2) blended in a single emitting layer of WOLED.…”