In a world where "bigger" pixels and "deeper" pixels dominate the discussions around smartphone sensors, Samsung has decided to switch … otherwise. The giant image sensor has revealed the world's first 0.7 µm pixel mobile image sensor, which allowed it to pack 43.7 megapixels in a sensor smaller than 5 mm wide.
The Samsung ISOCELL Slim GH1
To combine this small size with enough resolution to appeal to 2019 speculation, Samsung is taking advantage of its Tetracell technology, which makes the Slim GH1 two sensors-in-one by using a square filter to group squares of four pixels together.
In good light, the distance elimination algorithm allows this image sensor to capture a full 43.7MP images; when the light goes down and those small 0.7µm pixels could create serious noise problems, the quad bike design allows the sensor to produce better, 10.9MP images with "higher light sensitivity equivalent to 1.4µm pixel image sensor. "The best of both worlds.
And since this reduced Tetracell resolution is still sufficient to cover 4K, ISOCELL Slim GH1 promises "more detailed backgrounds when recording high definition videos or 60T selfies (fps)." 
This is another impressive achievement for Samsung, which has made some major gains in the game of the smartphone's image sensor with its ultra-high resolution 64MP and 108MP ISOCELL Bright images, which take advantage of the same Tetracell technology, For ISOCELL Slim, Samsung just downloaded the script using ashtata technology to pack more resolution and performance in a smaller chip.
The hope is that this sensor "will allow for lighter and more modern designs as well as an excellent imaging experience in tomorrow's smartphones."
Oh, and if you're wondering if this technology will soon transform it in "real" cameras, the answer seems to be: Sony has already developed a 61MP full-frame Quad-Bayer at 61MP on a Sony a7R IV that can deliver the same "best of both worlds" approach for much more Larger and more capable cameras.