A method to make light-emitting diode (LED) units include arranging LEDs in a pattern, forming an optically transparent spacer layer over the LEDs, forming an optically reflective layer over the LEDs, and singulating the LEDs into LED units. The method may further include, after forming the optically transparent spacer layer and before singulating the LEDs, forming a secondary light-emitting layer that conforms to the LEDs, cutting the LEDs to form LED groups having a same arrangement, spacing the LED groups on a support, and forming the optically reflective layer in spaces between the LED groups.