The biggest technical problem left to overcome has been the limited lifetime of the devices. Red and green OLED elements already had lifetimes of well over 20,000 hours but blue OLED lifetimes had lagged significantly behind. However, in May 2005, Cambridge Display Technology announced a blue OLED with a lifetime of over 100,000 hours and 100 cd/m². Unfortunately, according to the CDT press release "Lifetimes for devices made using the new blue materials at 200cd/m², 300cd/m² and 400cd/m² are greater than 25,000 hours, 10,000 hours and 6,000 hours respectively". 400 cd/m² is the brightness of LCD panels currently on the market.
According to Kodak, which is developing small molecule OLED, lifetime problems are not so significant for that type of OLED, mainly as a result of doping the base material of the OLEDs, which, they claim, has led to much better device performance both electrically and optically. Universal Display for example have produced a blue OLED that has a lifetime of 10,000 hours. There are still a number of problems to overcome though. One of these is intrusion of water into displays which damages and destroys the organics. Therefore, improved sealing processes are important for practical manufacturing. Also, efficient outcoupling of waveguided light within the substrates is an area of continued research.
Commercial development of the technology is also restrained by patents held by Kodak and other firms, requiring other companies to acquire a license. In the past, many display technologies have become widespread only once the patents had expired; aperture grille CRT is a classic example.
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