LunaLEC Liquid Light Concept: Light Made Easy

LunaLEC Liquid Light: Enhancing the Next Generation Packaging, Illumination and Signage

In the scientific community, the LunaLEC liquid light concept is known as the Light-Emitting Electrochemical Cell (LEC). From a distance and a layman’s perspective, this technology is very similar to the Organic Light-Emitting Diode (OLED), as both technologies use a flat planar lighting structure in which the light-emitting organic layer is sandwiched between two conductive electrodes.

The LEC Theory – Basic Functions

The LEC only needs one active layer (AL) positioned between two electrodes in a “sandwich structure”. Both electrodes and the AL can be deposited from solution in ambient condition:

 

Lighting-Inspiration.com_LunaLEC_Sandwich  Materials

The LEC’s Basic Function: Sandwich Materials

The active layer is a blend of active components dissolved in solvents, which solvents are optimized for different deposition techniques. The active components in the active layer are a fluorescent and semiconducting “conjugated polymer” and an electrolyte (dissolved salt).

 

LunaLEC coloured ink before deposition

LunaLEC coloured ink before deposition

In-situ doping: opportunities for the LEC-technology

Utilizing ‘In-situ doping – i.e. dopant atoms are introduced into a semiconductor during its growth. Most commonly, this takes place during epitaxial growth of semiconductor layers. This proces brings enhanced possibilities for LEC technology:

(1) Recombination of electrons and holes in the devices is very efficient.
An efficient recombination of electrons and holes leads to only a small need for over-potential to drive the light-emission. It comes with a low turn-on voltage, i.e. 3-6 VDC for all emission colors;

(2) Functionality of the electrodes is not critical for the injection of electrons and holes.
As opposed to other lighting technologies, LEC devices can utilize air-stable electrodes for both cathode and anode. It means that there is no need for a clean room environment or vacuum to deposit the electrodes. From a solution perspective, there are also possibilities to use electrodes;

(3) Self-Adjustment of Layers
The doping layers will self-adjust to a common distance between n-front and p-front throughout the device regardless of the variations of thickness of the active layer. It is also possible to utilize 3D printing methods with uneven deposition;

(4) Energy Efficient Operations
With triplet harvesting most of the energy most of the energy supplied is used in the efficient recombination of electrons and holes.

 

LunaLEC Liquid Light Technology: first sample parts

LunaLEC was founded in 2012 in order to develop lighting panels from the LEC-research performed by professors Nathaniel Robinson at Linköping University and Ludvig Edman at Umeå University. Here’s a small movie showing the first samples of LunaLEC liquid light technology, as prepared for its Printoo campaign:

At Lighting-Inspiration.com we keep following this newborn lighting technology with great interest and are curious to see how it will establish itselves within the rising potential for planar lighting technologies in the next decade!