Sunkook Kim

Phototransistors based on multilayer MoS(2) crystals are demonstrated with a wider spectral response and higher photoresponsivity than single-layer MoS(2) phototransistors. Multilayer MoS(2) phototransistors further exhibit high room temperature mobilities (>70 cm(2) V(-1) s(-1) ), near-ideal subthreshold swings (~70 mV decade(-1) ), low operating gate biases (<5 V), and negligible shifts in the threshold voltages during illumination.

A low-power flexible organic light-emitting diode (OLED) display device based on low temperature color filters with a thin film encapsulated RGB OLED microcavity is achieved with high contrast ratios (up to 150 000:1 in dark ambient) and low power consumption (34% power saving compared to polarization film). Furthermore, a mechanical 10 000 times folding experiment with a folding radius of 1 mm demonstrates the mechanical reliability of the flexible OLED device.

Local-gate multilayer MoS2 phototransistors exhibit a photoresponsivity of up to 342.6 A W(-1) , which is higher by 3 orders of magnitude than that of global-gate multilayer MoS2 phototransistors. These simulations indicate that the gate underlap is critical for the enhancement of the photoresponsivity. These results suggest that high photoresponsivity can be achieved in indirect-bandgap multilayer MoS2 phototransistors by optimizing the optoelectronic design.

Transition metal dichalcogenides (TMDs) layers of molecular thickness, in particular molybdenum disulfide (MoS 2 ), become increasingly important as active elements for mechanically flexible/stretchable electronics owing to their relatively high carrier mobility, wide bandgap, and mechanical flexibility. Although the superior electronic properties of TMD transistors are usually integrated into rigid silicon wafers or glass substrates, the achievement of similar device performance on flexible sub

Real-time temperature monitoring of individual blood packages capable of wireless data transmission to ensure the safety of blood samples and minimize wastes has become a critical issue in recent years. In this work, we propose flexible temperature sensors using silver nanowires (NWs) and a flexible colorless polyimide (CPI) film integrated with a wireless data transmission circuit. The unique design of the temperature sensors was achieved by patterning Ag NWs using a three-dimensional printed m

This paper presents ultrathin and highly sensitive input/output devices consisting of a capacitive touch sensor (Cap-TSP) integrated on thin-film-encapsulated active-matrix organic light-emitting diodes (OLEDs). The optimal structure of the electrically noise-free capacitive touch sensor, which is assembled on a thin-film-encapsulated active-matrix OLED (AMOLED) display, is obtained by investigating the internal electrical field distribution and capacitance change based on the Q3D Extractor mode

Plant growth and development are negatively affected by a wide range of external stresses, including water deficits. Especially, plants generally reduce the stomatal aperture to decrease transpiration levels upon drought stress. Advanced technologies, such as wireless communications, the Internet of things (IoT), and smart sensors have been applied to practical smart farming and indoor planting systems to monitor plants’ signals effectively. In this study, we develop a flexible polyimide (PI)-ba

In this study, we propose a method for improving the stability of multilayer MoS₂ field-effect transistors (FETs) by O₂ plasma treatment and Al₂O₃ passivation while sustaining the high performance of bulk MoS₂ FET. The MoS₂ FETs were exposed to O₂ plasma for 30 s before Al₂O₃ encapsulation to achieve a relatively small hysteresis and high electrical performance. A MoO_x layer formed durin

Fully transparent thin-film transistors (TFTs) based on well-aligned single-walled carbon nanotube (SWCNT) arrays with indium tin oxide (ITO) electrodes are achieved. The fully transparent SWCNT-TFTs could be attractive candidates for future flexible or transparent electronics.

Abstract Wearable devices are widely used in the smart healthcare monitoring system to detect changes in user parameters through applications such as wristwatches, bands, and clothing electronic skin. In addition, multimode devices enable monitoring of vital signs, helping diagnose and prevent diseases. A wearable device detects the user's biological signals such as body temperature, movement, heartbeat, and humidity level, transmits the information to the mobile phone, and sends the information

Thin-film transistors (TFTs) based on multilayer molybdenum diselenide (MoSe₂ ) synthesized by modified atmospheric pressure chemical vapor deposition (APCVD) exhibit outstanding photoresponsivity (103.1 A W^-1 ), while it is generally believed that optical response of multilayer transition metal dichalcogenides (TMDs) is significantly limited due to their indirect bandgap and inefficient photoexcitation process. Here, the fundamental origin of such a high photoresponsivity

Optically transparent and mechanically flexible thin-film transistors have recently attracted attention for next generation transparent display technologies. Driving and switching transistors for transparent displays have challenging requirements such as high optical transparency, large-scale integration, suitable drive current (I(on)) in the microampere range, high on/off current ratio (I(on)/I(off)), high field-effect mobility, and uniform threshold voltage (V(th)). In this study, we demonstra

Transition-metal dichalcogenides (TMDs) in flexible technology can offer large-area scalability and high-density integration with a low power consumption. However, incorporating large-area TMDs in a flexible platform is lacking in state-of-the-art data storage technology owing to the high process temperature of TMDs. Low-temperature growth of TMDs can bridge mass production in flexible technology and reduce the complexity of the transferring process. Here, we introduce a crossbar memory array en