| AVS 60th International Symposium and Exhibition | |
| Thin Film | Monday Sessions |
| Session TF+EN-MoM |
| Session: | ALD for Energy |
| Presenter: | S. Cha, Seoul National University, Republic of Korea |
| Authors: | G. Cho, Seoul National University, Republic of Korea S. Cha, Seoul National University, Republic of Korea J. Paek, Seoul National University, Republic of Korea J. Park, Seoul National University, Republic of Korea I. Change, Seoul National University, Republic of Korea |
| Correspondent: | Click to Email |
Solid Oxide Fuel Cells (SOFCs) were considered most promising solutions for the next generation power generator. SOFCs usually operate at high temperature due to poor ionic conductivity of their oxide electrolyte. This high operation temperature caused many drawbacks like requirement of high cost thermal-resistive materials, thermal degradation and long start-up time.
There were many investigations to lower the operation temperature of SOFCs to solve aforementioned drawbacks. Among many researches to lower operation temperature, thin film SOFCs showed most impressive outcomes. The thickness reduction of oxide electrolyte by thin film technique led to the ohmic resistance reduction and low operation temperature of SOFCs. Due to thin electrolyte, thin film SOFCs showed high performance at low temperature. Thin film SOFCs were fabricated by thin film technique, i.e. sputter, pulsed laser deposition (PLD), chemical vapor deposition (CVD), atomic layer deposition (ALD) and etc.
The ALD was an advanced thin film technique for various applications. The unique characteristic of ALD, self-limiting growth, led to many advantages, i.e. precise thickness control, excellent step coverage, film uniformity and large area capability. In thin film SOFCs, very uniform and conformal thin film electrolyte was prepared by ALD to remove pin-holes and defects in electrolyte. Most well known materials of electrolyte for SOFCs, Yttria-Stabilized Zirconia (YSZ) was successfully fabricated by combination of deposition processes for Y2O3 and ZrO2 of ALD.
In this research, we prepared thin film YSZ electrolyte for LT-SOFCs via ALD and applied to LT-SOFCs. First, chemical and physical characteristics of thin film YSZ related with different deposition conditions were investigated to confirm the most appropriate YSZ electrolyte for LT-SOFCs. After investigations of thin film YSZ electrolyte, LT-SOFCs with ALD-fabricated YSZ electrolyte were prepared. Nano-porous Anodizing Alumina Oxide (AAO) template was used as the supported structure. Platinum was used for both anode and cathode catalyst to suppress activation loss and current collection resistance. Then, effects of different ALD-fabricated thin film YSZ electrolyte to LT-SOFCs, i.e. open circuit voltage, power density, and electrochemical impedance spectroscopy were investigated.