Nanomarkets released a new report covering the transparent OLED display market (Transparent OLED Displays – 2014) in which they forecast that the market will be dominated by LCDs in the next several years, but OLED participation will rapidly pick up. By 2019, transparent OLED display sales will reach almost $150 million, and this will grow to almost $700 million by 2021.
There are still some major challenges on the road to transparent OLEDs, but these issues are gradually being solved. The major challenges, according to Nanomarkets, are ITO replacement and excessive light loss compensation.
Simple transparent PMOLED displays are already entering the market. Kairos for example are developing a Smartwatch which is a mechanical watch that has a transparent OLED on top. Kairos' watch uses a 1.4" full-color round OLED (40% transparent) Lonshine's upcoming Halo smartwatch is also based on the same idea, and it uses a similar round T-OLED (96x96, 256-color).
The first consumer device with a transparent OLED was Lenovo's S-800 feature phone, introduced in 2011. It used a 2-inch transparent PMOLED (320x200) produced by Futaba. I reviewed the display (with a development kit by 4D Systems) which is sadly no longer in production.
Larger transparent AMOLED displays are on their way. LG is aiming to develop a 60" UHD flexible and transparent OLED by 2017. The 2017 panel will have a transmittance of over 40% and a curvature radius of 100R. A few months ago LG unveiled 18" transparent AMOLED prototypes.