High pixel density structures and methods of making

A display, comprising:

• a first pixel, the first pixel comprising a first set of four subpixels, each subpixel of the first set of four subpixels having a light-emitting diode (LED) between adjacent isolation structures, wherein the adjacent isolation structures define subpixel wells with each well including a respective LED, three of the subpixels of the first set of four subpixels include quantum dot materials that fill the respective subpixel wells and that are configured to emit different colors, and a fourth subpixel of the first set of four subpixels includes a quantum-dot-free matrix material filling the respective subpixel well;
• and
• a second pixel, the second pixel comprising a second set of four subpixels, each subpixel of the second set of four subpixels having an LED between adjacent isolation structures, wherein the adjacent isolation structures define subpixel wells with each well including a respective LED, three of the subpixels of the second set of four subpixels include quantum dot materials that fill the respective subpixel wells and that are configured to emit different colors, and a fourth subpixel of the second set of four subpixels includes a quantum dot material that fills the respective subpixel well and that is configured to emit a same green or red color as the quantum dot material of one of the three subpixels of the second set of four subpixels.