Optoelectronic Memory Cell with Solid Electrolyte
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current memory technologies, such as DRAM, require frequent refreshing to maintain stored information due to leakage currents, while nonvolatile memories like EEPROMs occupy more space and have slower response times compared to volatile memories.
Innovation Solution
A nonvolatile optoelectronic memory device with a memory cell comprising two electrochromic electrodes separated by a solid electrolyte, which switches between optoelectronic states via a redox reaction triggered by an electric field, allowing for stable information storage without the need for refreshing and offering high storage capacity and fast access times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If DRAM is used for memory storage, then fast access time is achieved, but information is lost due to leakage current requiring frequent refreshing
Solution Approach 1:
The patent changes the physical state of the memory cell from volatile (DRAM) to nonvolatile by introducing a solid electrolyte and utilizing redox reactions. The memory cell transitions from storing charge temporarily to maintaining stable optoelectronic states through electrochemical reactions, fundamentally altering the retention parameter while preserving fast access characteristics.
Solution Approach 2:
The patent replaces the electrical charge storage mechanism of DRAM with an electrochemical redox system. Instead of relying on capacitor charge retention, the invention uses oxidation-reduction reactions in the solid electrolyte to create stable, nonvolatile states that can be read optically, substituting the electrical mechanism with a combined electrochemical-optical system.
2Reliability
If EEPROM is used for nonvolatile memory storage, then information retention without refreshing is achieved, but device occupies more space and has slower response time
Solution Approach 1:
The patent divides the memory cell into distinct functional layers: electrochromic electrodes for state representation, solid electrolyte for ion transport and redox reactions, and transparent conductive layers for electrical control. This segmentation allows each component to be optimized independently, achieving nonvolatile storage with fast response by separating the writing (electrical) and reading (optical) functions.
Solution Approach 2:
The patent introduces an optical dimension to the traditionally electrical memory system. By making the electrodes electrochromic and the electrolyte transparent to readout wavelengths, the invention enables optical detection of the memory state, adding a new dimension for information retrieval that is faster and nondestructive compared to electrical readout in conventional EEPROM.
3Speed
If solid electrolyte with redox reaction is used, then nonvolatile storage with fast access is achieved, but device complexity increases
Solution Approach 1:
The solid electrolyte layer serves multiple functions simultaneously: it acts as the medium for redox reactions, provides ion transport pathways, serves as an insulator between electrodes, and enables optical transparency for readout. This multi-functionality reduces the need for additional separate components, managing device complexity while achieving nonvolatile fast memory performance.
Solution Approach 2:
The patent employs composite material structures: electrochromic electrodes combining conductive and optically active properties, and solid electrolytes with specific ion conductivity and optical transparency. These composite materials integrate multiple required properties within single layers, reducing overall device complexity compared to using separate functional layers for each property.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves the storage capacity of DRAM with the nonvolatility of EEPROMs, maintaining information without refreshing and providing faster response times than other types of RAMs, while withstanding high manufacturing and operating temperatures.
Implementation Method 1
switches between optoelectronic states via a redox reaction triggered by an electric field
Implementation Method 2
two electrochromic electrodes separated by a solid electrolyte, which switches between optoelectronic states
Data Source
AI summary
A memory device may include an access transistor, and a memory cell configured to store an item of information. The memory cell may include first and second electrodes configured to have different optoelectronic states corresponding respectively to two values of the item of information, and to switch between the different optoelectronic states based upon a control signal external to the memory cell, the different optoelectronic states being naturally stable in an absence of the control signal. The memory cell may also include a solid electrolyte between the first and second electrodes.