Generally, Au electrodes are the preferred top metal electrodes in most perovskite solar cells (PSCs) because of their appropriate work function for hole transportation and their resistance to metal-halide formation. However, for the commercialization of PSCs, the development of alternative metal electrodes for Au is essential to decrease their fabrication cost. Ag electrodes are considered one of the most suitable alternatives for Au electrodes because they are relatively cheaper and can provide the necessary stability for oxidation. However, Ag electrodes require an aging-induced recovery process and react with halides from perovskite layers. Herein, we propose a bilayer Au/Ag electrode to overcome the limitations of single Au and Ag metal electrodes. The performance of PSCs based on bilayer electrodes is comparable to that of PSCs with Au electrodes. Furthermore, by using the bilayer electrode, we can eliminate the aging process, normally an essential process for Ag electrodes. This study not only demonstrates an effective method to substitute for expensive Au electrodes but also provides a possibility to overcome the limitations of Ag electrodes.

Abstract
1. 서 론
2. 실험방법
3. 결과 및 고찰
4. 결 론
References

• 이준영(경북대학교 에너지공학부) | Junyeong Lee (School of Energy Engineering, Kyungpook National University, Daegu 41566, Republic of Korea)
• 조성진(경북대학교 에너지공학부) | Sungjin Jo (School of Energy Engineering, Kyungpook National University, Daegu 41566, Republic of Korea) Corresponding author