Counter electrode for an electrochromic device
AssigneeApple Inc.
InventorsErik J. Bjornard, Tingjun Xu
Life of this patent
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Abstract
An imaging system for a portable electronic device includes a variable aperture between a lens group and an image sensor. The variable aperture is defined by an electrochromic stack that defines a switching region and a central non-switching region. The electrochromic stack is defined by a layer of electrochromic material in which an electrochromic crystallite dispersion (e.g., nickel oxide) is suspended in a field of a lithiated ion conductor layer (e.g., lithiated tungsten nickel oxide).
Claims14
A stack capable of defining at least a portion of an electrochromic layer of an imaging system in a portable electronic device, the stack comprising:
- an optically transparent substrate;
- a metal oxide layer disposed onto the optically transparent substrate;
- and
- a precursor layer disposed onto the metal oxide layer to a first thickness, the precursor layer capable of defining an electrochromic counter electrode of the electrochromic layer of the imaging system when annealed, the precursor layer comprising a lithiated transition metal oxide stack defined by alternating layers of a first transition metal oxide and a second transition metal oxide;
- wherein:
- the first transition metal oxide is nickel oxide;
- the second transition metal oxide is tungsten oxide or tantalum oxide;
- each layer of first transition metal oxide is disposed to a second thickness;
- and
- each layer of second transition metal oxide is disposed to a third thickness.
A method of forming an anneal precursor stack and a counter electrode of an electrochromic layer of an imaging system in a portable electronic device, the method comprising:
- forming the anneal precursor stack by:
- selecting an optically transparent substrate;
- disposing a first metal oxide layer onto a surface of the optically transparent substrate;
- forming a precursor layer, to a first thickness, over the metal oxide layer by alternatingly disposing:
- a second thickness of a first transition metal oxide over an uppermost layer of the precursor layer;
- and
- a third thickness of a second transition metal oxide over the uppermost layer of the precursor layer;
- wherein lithium ions are diffused to a selected concentration within at least one of the first transition metal oxide or the second transition metal oxide;
- annealing the anneal precursor according to an anneal plan to cause the precursor layer to define the counter electrode comprising a diffusion of crystallites of the first transition metal oxide suspended in a field of lithiated second transition metal oxide;
- dispose a second metal oxide layer over the counter electrode;
- and
- etch at least one of the first metal oxide layer or the second metal oxide layer to define a switching region and a non-switching region of the counter electrode, wherein:
- the first transition metal oxide is nickel oxide;
- and
- the second transition metal oxide is tungsten oxide or tantalum oxide.
A method of forming an anneal precursor stack to define a counter electrode of an electrochromic layer of an imaging system in a portable electronic device, the method comprising:
- disposing a first metal oxide layer onto a surface of a substrate;
- forming a precursor layer, to a first thickness, over the metal oxide layer by alternatingly disposing:
- a second thickness of a first transition metal oxide over an uppermost layer of the precursor layer;
- and
- a third thickness of a second transition metal oxide over the uppermost layer of the precursor layer;
- and
- annealing the anneal precursor according to an anneal plan to cause the precursor layer to define the counter electrode comprising a diffusion of crystallites of the first transition metal oxide suspended in a lithiated material, wherein:
- the first transition metal oxide is nickel oxide;
- and
- the second transition metal oxide is tungsten oxide or tantalum oxide.
Dependencies are inferred from the claim text.