You’re measuring the phosphor, not the die, when pointing an ir thermometer at it. The phosphor can be much hotter than the die (see Nichia E21A for example). I think you need a blue LED to measure the die temp.
You’re measuring the phosphor, not the die, when pointing an ir thermometer at it. The phosphor can be much hotter than the die (see Nichia E21A for example). I think you need a blue LED to measure the die temp.