With the rapid development of the information-oriented society and the expansion of the use of computers, energy consumption continues to increase, and reducing the energy consumption of semiconductor devices has become an urgent issue.

　This group focused on the structure and operating mechanism of all-solid-state lithium batteries, and conceived a low-energy voltage-recording memory element that stores information as voltage.This element makes the charge state and the discharge state of the battery correspond to "0" and "1" of the memory, and the smaller the battery capacity, the smaller the energy consumption, and the better the memory element.

　Nickel was selected as the positive electrode material, and a memory device with a thin-film laminated structure similar to that of all-solid-state lithium was manufactured.As a result, it was confirmed that ultra-thin nickel oxide was spontaneously formed on the nickel electrode and operated as an all-solid-state lithium battery having a very small capacity, that is, a memory element.

　The energy consumption required for memory operation is calculated to be about 50/1 of the DRAM (Dynamic Random Access Memor) used in current personal computers, achieving ultra-low energy consumption operation.It was also found that this memory operates as a ternary recording memory that can store three different voltage states (low voltage, medium voltage, and high voltage).It was also confirmed that these are caused by the multi-step reaction that occurs between the nickel oxide film and the lithium ion.

　Multi-value recording, which leads to reduction of energy consumption and high density of recording, is the key to energy-saving computing, and this achievement is expected to be a major step toward the practical application of memory devices with such characteristics. Will be done.

Paper information:[ACS Applied Materials and Interfaces] Low energy consumption three-valued memory device inspired by solid-state batteries