Jae Heon Shin

Electron beam irradiated silver nanowires for a highly transparent heater

Transparent heaters have attracted increasing attention for their usefulness in vehicle windows, outdoor displays, and periscopes. We present high performance transparent heaters based on Ag nanowires with electron beam irradiation. We obtained an Ag-nanowire thin film with 48 ohm/sq of sheet resistance and 88.8% (substrate included) transmittance at 550 nm after electron beam irradiation for 120 sec. We demonstrate that the electron beam creates nano-soldering at the junctions of the Ag nanowires, which produces lower sheet resistance and improved adhesion of the Ag nanowires. We fabricated a transparent heater with Ag nanowires after electron beam irradiation, and obtained a temperature of 51 °C within 1 min at an applied voltage of 7 V. The presented technique will be useful in a wide range of applications for transparent heaters.

Effects of Nb2O5 and SiO2 buffer layers on the suppression of potassium out-diffusion into indium tin oxide electrode formed on chemically strengthened glass

We have investigated the electrical properties of indium tin oxide (ITO) thin films deposited on chemically strengthened glass (CSG) substrate by room-temperature ionized physical vapor deposition (IPVD). The ITO thin film on the CSG substrate shows a higher sheet resistance after high-temperature anneal process (>200 °C) possibly due to the out-diffusion of potassium ions (K+) from the CSG. We have improved the electrical properties of the ITO thin film by inserting Nb2O5/SiO2 buffer layers between the ITO layer and the CSG substrate. As a result, a protected and index-matched 30-nm-thick ITO thin film with sheet resistance less than 120 Ω/sq and optical transmittance higher than 90% (at 550 nm) has been achieved.