A report from Korean news outlet The Bell (via Sammobile) says that Samsung Display is currently in the process of producing huge 6.9-inch AMOLED panels for Huawei's next flagship smartphone, which is likely going to be the Mate 20

A 6.9-inch screen would put the Mate 20 on borderline tablet territory, and will certainly give it the title of the largest screen seen on a smartphone. While the full technical specs, including resolution, of the panel haven't been revealed, it's believed they are flat panels as opposed to curved. 

While the idea of a 6.9-inch screen may seem a bit daunting, the phone itself may only be a tiny bit bigger, as Huawei will no doubt opt for a notch design - or maybe even completely edge-to-edge with a clever way of hiding the camera - and may have developed a way of slimming the bezels down to minute proportions.

Large screens are favoured by customers in China, where Huawei is the most popular brand, most likely because Chinese lettering takes up more space on the screen. Both Samsung and Apple are expected to up the screen sizes on their devices later this year too, with 6.38- and 6.46-inch screens expected for the Galaxy Note 9 and iPhone X Plus respectively. 

The report says that Samsung Display will begin supplying the new AMOLED panels to Huawei in the third quarter of 2018, which tallies up with the launch of the Mate 10 and Mate 10 Pro, which were unveiled in October and available later that month and in early November. We would therefore suggest the Mate 20 - and possible Mate 20 Pro, although this isn't confirmed - will follow a similar launch cycle.