Samsung just detailed further the 108MP sensor it announced back in august as part of a collaboration with Xiaomi over the Mi Note 10 by issuing a press release touting the wonders of its new "108-megapixel ISOCELL Bright HMX, the industry’s first mobile image sensor to exceed 100 million pixels."
Accompanied by the promo video you can watch above, the sensor writeup mentions it uses the same Tetracell technology that Samsung applied for its 64MP Bright HMX sensors that bin four adjacent 0.8 micron pixels into a virtual 1.6 micron one.
That's still a far cry from the rumored technique we heard that the Galaxy S11+ will use, namely pixel-binning for a 3x3 neighbouring pixels grid instead of the 2x2 Tetracell tech that Samsung reiterates in the press release.
Unlike the summer press release that mostly focused on the Xiaomi collab, Samsung spent more time to explain ISOCELL Plus this time around as a technology for physically isolate the individual pixels to prevent crosstalk and interference.
In any case, rumors point to a tailored version of this 108MP Bright HMX sensor to land in the top-shelf Galaxy S11+ at least, so it makes sense to keep some of its wonders under wraps before the announcement.
What Samsung did share, apart from the improved instant autofocus feature, is the ability to overcome the poor low-light sensitivity of small pixels by binning a few of them into one, and still arriving at high detail and resolution levels: