A method for selective patterning of quantum dots in the production of optical devices

A patterning method for the production of electronic/electro-optical devices based on nanoparticles that can convert optical energy into electrical energy by photovoltaic or electrothermal mechanism, characterized by comprising the process steps of,

• i. depositing the material that will form the ionic lens on a substrate, on which electrodes and/or additional materials that will facilitate the transmission of electric current have been previously treated,
• ii. forming the desired sub-pixel pattern in the form of holes on the material that will form the ionic lens by patterning, and obtaining the ionic lens by aligning the holes that define the sub-pixel on the machined electrodes by using standard alignment methods,
• iii. forming the electrically charged nanoparticles in air, in a pure and discrete manner from other materials, by passing the liquid solution containing nanoparticles that can convert optical energy into electrical energy by photovoltaic or electrothermal mechanism, through the process of electrospray ionization, and sending it to the surface desired to be patterned,
• iv. Focusing the nanoparticles through the holes that define the sub-pixel by means of electric force, and thereby patterning the majority of the quantum dots on the desired electrodes by means of the electrical charges deposited thereon by the ionic lens in case the ionic lens is an insulator lens, and by means of the electrical potential applied thereon in case the ionic lens is a conductive lens,
• v. Removing the layer acting as an ionic lens from the substrate surface by means of a suitable solvent, abrasive, or corrosive,
• vi. Repeating the (i-v) steps for each type of nanoparticles sequentially to create different sub-pixels.

A method of producing a monochrome or multi-color display with both high display performance and high performance of each pixel, wherein both the cross-contamination between different sub-pixel types and contamination from chemicals used in production for each sub-pixel are low, electroluminescent quantum dots consisting of pixels containing quantum dots are deposited directly onto target pixels containing electrodes, characterized by comprising the process steps of,

• a. depositing photoresist material on a substrate surface on which electrodes have been treated,
• b. forming the desired sub-pixel pattern in the form of holes on the photoresist material by using the photolithography process, and obtaining the insulator lens,
• c. aligning the holes that define sub-pixel on metal electrodes by using standard alignment methods,
• d. sending zinc oxide (ZnO), magnesium-doped zinc oxide (Mg-doped ZnO) or other nanoparticles that can facilitate the electron flow to quantum dots and act as electron transfer layer to the surface by electrospray ionization,
• e. focusing the nanoparticles through the holes that define the sub-pixel by electric force by means of the electric charges accumulated thereon by insulator lens, and thereby patterning the majority of the quantum dots on the desired electrodes,
• f. while the same insulator lens is still on the surface, sending the desired type of quantum dots to the surface by electrospray ionization, such that the insulating lens focuses a large part of the quantum dots on the holes that define the sub-pixel, and thereby patterning the quantum dots on the electron transfer layer,
• g. Removing the photoresist layer that acts as an insulator lens from the surface by means of a suitable solvent or photoresist remover,
• h. Patterning the quantum dots by repeating the previous processing steps appropriately for each different type of quantum dots desired to be used,
• i. After patterning, laying the hole transfer layer in a suitable gas environment and using a spinner,
• j. laying the hole injection layer,
• k. joining a substrate with electrodes on this stack that is formed.