Memristor applications
International Collaborative Research with IHP
Resistive random-access memory (RRAM or ReRAM) is a non-volatile memory type under development by a number of different companies, some of which have patented versions of ReRAM. The technology bears some similarities to CB RAM and phase change memory. In February 2012 Rambus bought a ReRAM company called Unity Semiconductor for $35 million. Panasonic launched a ReRAM evaluation kit in May 2012, based on a tantalum oxide 1T1R (1 transistor - 1 resistor) memory cell architecture.
In 2013, Crossbar introduced a prototype of RRAM as a chip about the size of a postage stamp that can store 1 TB of data. According to an August 2013 interview with Crossbar, the large-scale production of their RRAM chips is scheduled for 2015.
Different forms of ReRAM have been disclosed, based on different dielectric materials, spanning from perovskites to transition metal oxides to chalcogenides. Even silicon dioxide has been shown to exhibit resistive switching as early as 1967, and has recently been revisited.
In this region, I have been focusing on the mechnism of resistive switching and development of selector for reliable ReRAM applications.
3. Optic Devices (광 소자)
- Transparent Conductive Electrode (TCE)
- GaN based LED Device
GaN based LED
Gallium nitride (GaN) is a binary III/V direct bandgap semiconductor commonly used in bright light-emitting diodes since the 1990s. The compound is a very hard material that has a Wurtzite crystal structure. Its wide band gap of 3.4 eV affords it special properties for applications in optoelectronic, high-power and high-frequency devices. For example, GaN is the substrate which makes violet (405 nm) laser diodes possible, without use of nonlinear optical frequency-doubling.
Its sensitivity to ionizing radiation is low (like other group III nitrides), making it a suitable material for solar cell arrays for satellites. Military and space applications could also benefit as devices have shown stability in radiation environments. Because GaN transistors can operate at much higher temperatures and work at much higher voltages than gallium arsenide (GaAs) transistors, they make ideal power amplifiers at microwave frequencies.
In this region, I have been focusing on the effiency of light output power for UV LEDs by developing novel transparent conductive electrodes (TECs).