UV LED encapsulant musing.

My hair wasn’t glowing. I needed to fix this.

I have this LED blacklight bulb in a desk lamp at my bench at work and it normally makes my hair glow nicely. In case you’re wondering— it’s thanks to the Iroiro Colors 300 series dyes. Neon Yellow, Neon Red, and Neon Pink are probably the brightest. I’m always tempted to just throw Neon Pink over my whole head because it looks so nice, but I am absolutely incapable of deciding on just one color so I continue to be a rainbow.

Anyway, this is what I get when it’s working:

I don’t turn the blacklight off, so it was just kinda cooking there for over a year. Eventually it became a dark purple light that didn’t make any magic.

New bulb
Old bulb

The most noticeable difference is that the encapsulant on the “filament” arrays has darkened right over each emitter.

Old bulb, Well Done
New bulb, the encapsulant is water clear

I had read a while back that some of the nasty but revolutionary UV-A emitters from Nichia, when they first came on the market, were using a metal TO-18 can with a quartz end window to avoid this.

I wonder how many other LED products may still suffer this degradation? I will say I got a good amount of life out of this $12 bulb so I’m not exactly mad, but I feel like if whoever made the “filaments” had used a better goopus on top of the array, it’d still be working fine.

As for the old bulb, I still like its weird violet glow and might try to scrounge up another weird fixture to put it in like this funky 3d printer-activated flicker lamp. I swear I can also see the HVAC chiller out back cycling in its brightness level.

I used to hate this thing but it’s slowly grown on me