Since Nikon started making digital SLRs they have predominantly used Sony CCD and CMOS sensors, especially in their prosumer and professional cameras.
The Nikon D850 has been rumored to not be using a Sony CMOS sensor and there have been plenty of unconfirmed reports that they may in fact be using sensors made by Israeli company TowerJazz, a company that has made sensors for Leica in the past.
It looks like we may have our first confirmation from the company itself that they are indeed working with Nikon on image sensors. Nikon Rumors reports that during Q3 financial results conference call a few days ago, that the CEO of TowerJazz had this to say.
In the CMOS image sensor market we are investing today in technology for three main directions; next-generation global shutter technology for the industrial sensor market; Backside Illumination and stack wafers for the high-end photography market; and special pixel technology for the automotive market.
In the digital SLR market we engage with one of the leaders in the world in the development of their next-generation sensors. And in parallel on track with our 300 millimeter Backside Illumination stack wafer technology development with outstanding pixel performance.
As Nikon Rumors points out, there are only 3 DSLR manufacturers left, Nikon, Pentax (Ricoh) and Canon. We all know Canon manufactures their own sensors for their DSLRs. With all due respect to Pentax, they probably don't fit into the “leaders of the world” category from the statement above.
It will be interesting to see what sensor Nikon puts into their upcoming full frame mirrorless camera.