A few months ago it was reported that LG will unveil a 77" OLED TV at the IFA 2013 exhibition - and today indeed the company unveiled a 77" curved UHD (4K) WRGB OLED TV panel. This is just a prototype, but still a great technology feat by LGD:
So - this is the world's largest OLED ever shown (the previous biggest one was AUO's 65" panel shown at SID 2013). It is also the world's highest resolution OLED at 4K (Samsung also has a UHD OLED panel on display at the exhibition).