YMTC, a Chinese 3D NAND maker, is not only ramping up production of flash memory at a rapid pace, but does so using silicon wafers ... of its own homegrown blank wafers, which are then used ...

Since the chips are so small, hundreds are made on a single silicon wafer at once. After all the patterns have been faithfully reproduced on to the chips, the wafer is sliced up into individual chips.

For comparison, a reference cell with a polished front surface and without the black silicon wafer achieved an efficiency of 11.5%, an open-circuit voltage of 600 mV, a short-circuit current ...