Also, you didn't reveal if this needed to be a smart phone. If not, shop for the old school black and white LCD screens like we had back then. I see a few on the front faces of some flip phones.
I want to buy a new cell phone. My only requirement is that the display must be easily visible in direct sunlight (like a Kindle).
Do you know what an OLED TV is?
CNET explains how OLED technology differs from regular TVs, and what you need to know to make the right shopping decision.