Displays with collimated light sources and quantum dots

A display, comprising:

• a light source configured to produce pump light;
• display layers that form an array of pixels configured to display images in response to the pump light, wherein the display layers include:
• a first layer having at least first quantum dot elements of a first color and second quantum dot elements of a second color;
• a second layer having at least first color filter elements of the first color that overlap the first quantum dot elements and second color filter elements of the second color that overlap the second quantum dot elements;
• a first substrate layer;
• and
• a second substrate layer, wherein the second layer is interposed between the first substrate layer and the second substrate layer;
• and
• a filter layer interposed between the first layer and the light source, wherein the filter layer is configured to reflect light of the first and second colors and pass the pump light and wherein the second substrate layer has a portion with recesses.

A display, comprising:

• a light source that produces pump light;
• display layers that form an array of pixels configured to display images in response to the pump light, wherein the display layers include a first layer having at least red and green quantum dot elements and a second layer having at least red color filter elements that overlap the red quantum dot elements in red pixels of the array of pixels and green color filter elements that overlap the green quantum dot elements in green pixels of the array of pixels, wherein the first layer includes a metal matrix having openings that receive at least the red and green quantum dot elements, and wherein the red and green quantum dot elements of the first layer have a first index of refraction;
• a filter layer interposed between the first layer and the light source that reflects at least red and green light and that passes the pump light;
• and
• a layer of material between the first layer and the filter layer that has a second index of refraction that is less than the first index of refraction.