CN-115461873-B - Adjustable sub-pixel

Abstract

A light emitting device having pixels includes a first non-tunable sub-pixel configured to emit light of a first non-tunable wavelength and a tunable sub-pixel configured to emit light of a tunable wavelength. The tunable subpixel includes a primary luminescent material configured to emit light of a primary wavelength in response to a primary electrical input, and a tuning element configured to modify the primary wavelength to a secondary wavelength in response to a second electrical input, wherein the secondary wavelength is tunable.

Inventors

• S. Ramoscanero

Assignees

• 普列斯半导体有限公司
• 普列斯半导体有限公司

Dates

Publication Date

20260421

Application Date

20210427

Priority Date

20210427

Claims (11)

1. 1. A light emitting device having pixels, comprising: a first non-tunable subpixel configured to emit light of a first non-tunable wavelength, and A tunable sub-pixel configured to emit light of a tunable wavelength, wherein the tunable sub-pixel comprises: A primary luminescent material configured to emit light of a primary wavelength in response to a primary electrical input, and A tuning element configured to modify the primary wavelength to a secondary wavelength in response to a secondary electrical input, wherein the secondary wavelength is tunable; Wherein the primary luminescent material comprises luminescent molecules configured to emit light of a wavelength tunable between the primary wavelength and the secondary wavelength by applying an electric field via the secondary electrical input so as to influence a molecular topology of the luminescent molecules.
2. 2. The light emitting device of claim 1, further comprising a secondary luminescent material comprising luminescent molecules configured to convert the primary wavelength of light to a tertiary wavelength of light and emit the tertiary wavelength of light in response to a tertiary electrical input.
3. 3. The light emitting device of claim 2, further comprising a tertiary luminescent material comprising luminescent molecules configured to convert light of the tertiary wavelength to light of a quaternary wavelength and emit the light of the quaternary wavelength in response to a quaternary electrical input.
4. 4. The light-emitting device of claim 3, wherein the primary, secondary, and tertiary light-emitting materials emit light if the applied current is within a range and transmit light if the applied current is outside of the range.
5. 5. A light emitting device according to claim 2 or 3, wherein the tunable sub-pixel further comprises a light emitter that emits light of a light emitter wavelength, and wherein the primary luminescent material is further configured to modify the light emitted by the light emitter wavelength such that the light emitted by the primary luminescent material is at the primary wavelength.
6. 6. The light-emitting device of claim 1, wherein the primary luminescent material is dissolved in a host material.
7. 7. The light emitting device of claim 1, wherein the primary luminescent material is nanopatterned.
8. 8. The light emitting device of claim 1, wherein the pixel has a second non-tunable sub-pixel configured to emit light of a second non-tunable wavelength and a third non-tunable sub-pixel configured to emit light of a third non-tunable wavelength.
9. 9. The light emitting device of claim 8, wherein the first, second, and third non-adjustable sub-pixels each emit one of red, green, and blue light.
10. 10. The light emitting apparatus of claim 1, further comprising a controller configured to modify the secondary electrical input.
11. 11. The light emitting apparatus of claim 10, wherein the controller is further configured to modify the secondary electrical input in response to an input.

Description

Adjustable sub-pixel Technical Field The present disclosure relates to the field of display technology, including the configuration of subpixels. Background In most existing display technologies, the image is presented by fusion of pixels. Pixels typically have fixed properties such as color and spatial configuration. The pixels may be spatially arranged in groups, such as a stripe pattern, wherein the groups may comprise pixels of different colors, which may be combined to present an image of any color. For example, one common configuration is a ternary subpixel comprising a red subpixel, a green subpixel, and a blue subpixel. Any color within the gamut of the sub-pixels may be rendered by using a combination of three sub-pixels, or white light may be achieved using the sum of three pixels. Another example configuration is a set of four sub-pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel. The color of the sub-pixels is typically fixed, but may also degrade over time, lose brightness or change color. It may also be the case that the display may be used for applications requiring different resolutions or brightnesses. It is an object of the invention to provide an adjustable sub-pixel for correcting local defects, improving resolution or increasing brightness. The adjustable sub-pixels may also be used to modify the color gamut of the display. Quantum dots are known to emit light. In the case where an electron is excited from the valence band to the conduction band, a hole remains in the valence band. The electron-hole pairs thus generated are called excitons, and recombination of the electron and hole pairs may result in emission of photons. The energy of the emitted photons may be equal to the sum of the band gap energy, the binding energy of the holes and excited electrons, and the binding energy of the excitons. Electrons can be excited with absorption of photons of energy equal to the band gap, or by electrical excitation. Disclosure of Invention In this context, there is provided a light emitting device having a pixel including: a first non-tunable subpixel configured to emit light of a first non-tunable wavelength, and A tunable sub-pixel configured to emit light of a tunable wavelength, wherein the tunable sub-pixel comprises: A primary luminescent material configured to emit light of a primary wavelength in response to a primary electrical input, and A tuning element configured to modify the primary wavelength to a secondary wavelength in response to a secondary electrical input, wherein the secondary wavelength is tunable. In this way the color of the light emitted by the adjustable sub-pixels can be modified and the properties of the pixels can be modified. For example, the resolution, brightness or color gamut of the pixel may be modified, or local defects may be corrected. The primary luminescent material may comprise quantum dots. Advantageously, the quantum dots may emit light by electrical pumping or optically assisted electrical pumping. The tuning element may comprise a piezoelectric actuator that stresses the luminescent material to strain the quantum dots. In this way, the secondary wavelength can be modified in real time so that the color of the tunable sub-pixel can be adjusted in use. The secondary wavelength may be a function of strain, and the target wavelength for the secondary wavelength may correspond to the applied stress value. In this way, the modification of the secondary wavelength can be controlled such that the secondary wavelength is tuned to a specific value. The light emitting device may further include a controller configured to determine whether the secondary wavelength is equal to a target wavelength corresponding to the applied stress value, and in the event that the secondary wavelength is not equal to the target wavelength, modify the stress applied to the semiconductor material until the secondary wavelength is equal to the target wavelength. Advantageously, the secondary wavelength may be adjusted in case it is not at the desired value. The tunable sub-pixel may further comprise a light emitter emitting light of the light emitter wavelength. The quantum dots may also be configured to modify light emitted at the light emitter wavelength such that the light emitted by the quantum dots is at a primary wavelength. In this way, the quantum dots can be simultaneously optically and electrically pumped, which can increase optical gain, thereby improving color conversion efficiency. The secondary wavelength may be a function of strain and the target wavelength for the secondary wavelength may correspond to the applied stress value. In this way, the modification of the secondary wavelength can be controlled such that the secondary wavelength is tuned to a specific value. The tunable subpixel may further comprise a secondary luminescent material comprising quantum dots, wherein the secondary luminescent material may be configured