Hanwei Gao, left, and Biwu Ma, right, admire their new LED technology. Photo by Bruce Palmer/Florida State University
TALLAHASSEE, Fla., Nov. 17 (UPI) -- Florida State researchers have developed a cheaper, more efficient LED, or light-emitting diode, the technology that illuminates the modern, energy-efficient home and delivers the picture on most flat screen TVs.
The key to the light's cheaper, brighter glow is a newly developed class of materials called organometal halide perovskites.
"Early work suggested perovskites could be a promising material to build LEDs," physicist Hanwei Gao said in a press release. "But, the performance was not up to their potential. We believed there was significant room for improvement."
Gao and his colleague, chemical engineer Biwu Ma, spent months using synthetic chemistry to fine-tune the materials in the lab, tweaking the molecular architecture.
An diode is a material that has been atomically manipulated to allow electricity to only flow in one direction, like a one-way street current. When two one-way streets are forced onto each other, the electric energy escapes in the form of photons.
The power, color and efficiency of a diode's light-emitting properties is largely determined by the material its made with.
Gao and Ma designed a perovskite material capable of emitting 10,000 candelas per square meter when powered by 12 volts. The diodes in most computer screens put out just 400 candelas per square meter.
"Such exceptional brightness is, to a large extent, owing to the inherent high luminescent efficiency of this surface-treated, highly crystalline nanomaterial," Gao explained.
The organic-inorganic hybrid material is easily and quickly made, which the researchers hope will translate to cheap, scalable production. LEDs are much more efficient than other lighting sources, but adoption in the home has been slow-going due to their relative expense.
"If you can get a low cost, high performing LED, everyone will go for it," Ma said. "For industry, our approach has a big advantage in that earth abundant materials can be processed in an economic way to make the products."
The new diode material was recently described in the journal Advanced Materials.