Metrology for oled manufacturing using photoluminescence spectroscopy

An apparatus, comprising:

• a light source configured to generate an excitation light in the visible or near-visible spectrum;
• an optical assembly configured to direct the excitation light onto a photoluminescent (PL) layer, wherein the optical assembly comprises:
• an optical splitter configured to direct a first portion of the excitation light directed at a first measuring location to a first optical fiber and a second portion of the excitation light directed at a second measuring location to a second optical fiber;
• and
• a computing device configured to determine a concentration of a dopant of the first measuring location or the second measuring location.

An apparatus, comprising:

• a light source configured to generate an excitation light in the visible or near-visible spectrum;
• an optical assembly configured to direct the excitation light onto a photoluminescent (PL) layer, wherein the optical assembly comprises:
• an optic fiber configured to direct at least a first portion of the excitation light to a first measuring location on the PL layer and at least a second portion of the excitation light to a second measuring location on the PL layer;
• and
• a computing device configured to determine a concentration of a dopant of the first measuring location or the second measuring location.