Phosphorescent materials are based on the addition of a heavy-metal to the emissive materails, and most (if not all?) commercial materials use Iridium. The price of this rare metal has hit an all-time high last week.
Towards the end of last year, the price of one oz of Iridium was $1,760. Last week it hit $6,000 - the price jumped over 300% in just three months. Experts explain that the price has risen due to a disruption in the supply in South Africa (which supplies around 80% of the global market) and strong demand from the electrical and electrochemical sector.