Flexible electroluminescent devices
Embodiments of a flexible electroluminescent (EL) device are described. An EL device includes a device stack and a flexible substrate configured to support the device stack. The device stack can include a anode and a cathode, a quantum dot (QD) film positioned between the anode and the cathode and configured to produce light having a first peak wavelength. The device stack further includes a patterned insulating layer disposed on the anode and configured to form electrically active regions in the device stack and to control emission of the light from the EL device through the electrically active regions. The EL device further includes an encapsulation layer disposed on the cathode.
1 . A method of fabricating an electroluminescent (EL) device, the method comprising:
forming a patterned insulating layer on an anode layer of a flexible substrate, including:
depositing an insulating film using spin coating, inkjet printing, slot die coating, nozzle printing, or contact printing on the anode layer; and
patterning the insulating film on the anode layer using an inkjet-printed mask in a lithography process;
forming a quantum dot (QD) film on the patterned insulating layer;
forming a cathode layer on the QD film; and
forming an encapsulation layer on the cathode layer.
2 . The method of claim 1 , further comprising providing the flexible substrate as a polyethylene terephthalate (PET) and the anode layer as an indium-tin-oxide (ITO) layer.
3 . The method of claim 1 , wherein forming the patterned insulating layer comprises depositing a pre-cut or pre-patterned insulating film on the anode layer.
4 . The method of claim 1 , wherein forming the patterned insulating layer comprises depositing a self-adhesive layer of pre-cut or pre-patterned insulating film on the anode layer.
5 . The method of claim 1 , wherein forming the patterned insulating layer comprises:
depositing an insulating film using spin coating or inkjet printing on the anode layer; and
patterning the insulating film on the anode layer using an inkjet-printed mask in a lithography process.
6 . The method of claim 1 , wherein forming the patterned insulating layer comprises patterning an insulating film using offset lithography, gravure printing, or flexographic printing.
7 . The method of claim 1 , wherein forming the encapsulating layer comprises:
depositing a pressure sensitive adhesive (PSA) layer on the cathode layer; and
depositing a barrier film on the PSA layer.
8 . The method of claim 7 , wherein depositing the PSA layer and the barrier film comprises depositing materials with a water vapor transmission rate (WVTR) ranging from about 10.5 g/m2-day to about 10 g/m2-day.
9 . The method of claim 7 , wherein depositing the PSA layer and the barrier film comprises depositing flexible materials.
10 . The method of claim 7 , wherein depositing the barrier film comprises depositing a metal laminate or a metal foil.
11 . The method of claim 7 , wherein depositing the barrier film comprises depositing an optically transparent, reflective, or opaque material.
12 . A method of fabricating an electroluminescent (EL) device, the method comprising:
forming a layer of insulating regions and conductive regions on an anode layer of a flexible substrate, including:
depositing an insulating film using spin coating, inkjet printing, slot die coating, nozzle printing, or contact printing on the anode layer; and
patterning the insulating film on the anode layer using an inkjet-printed mask in a lithography process, wherein the insulating regions and the conductive regions are arranged in an alternating configuration;
depositing a quantum dot (QD) film on the layer of insulating regions and conductive regions;
forming a cathode layer on the QD film; and
forming a flexible encapsulation layer on the cathode layer.
13 . The method of claim 12 , further comprising providing the flexible substrate as a polyethylene terephthalate (PET).
14 . The method of claim 12 , wherein forming the layer of insulating regions and conductive regions comprises depositing a pre-cut or pre-patterned insulating film on the anode layer.
15 . A method of fabricating an electroluminescent (EL) device, the method comprising:
depositing an insulating layer on an anode of a flexible substrate;
forming openings in the insulating layer;
depositing a conductive layer on the insulating layer and in the openings;
forming a quantum dot (QD) film on the conductive layer;
forming a cathode on the QD film; and
forming an encapsulation layer on the cathode.
16 . The method of claim 15 , wherein depositing the insulating layer comprises depositing an epoxy material.
17 . The method of claim 15 , wherein forming the encapsulation layer comprises depositing a barrier layer on the cathode.
18 . The method of claim 17 , wherein depositing the barrier layer comprises depositing a metal laminate or a metal foil.
19 . The method of claim 17 , wherein depositing the barrier layer comprises depositing a flexible material.