Uniform TiO2 blocking layers (BLs) are fabricated using ultrasonic spray pyrolysis deposition (USPD) method. To improve the photovoltaic performance of dye-sensitized solar cells (DSSCs), the BL thickness is controlled by using USPD times of 0, 20, 60, and 100 min, creating TiO2 BLs of 0, 40, 70, and 100 nm, respectively, in average thickness on fluorine-doped tin oxide (FTO) glass. Compared to the other samples, the DSSC containing the uniform TiO2 BL of 70 nm in thickness shows a superior power conversion efficiency of 7.58±0.20% because of the suppression of electron recombination by the effect of the optimized thickness. The performance improvement is mainly attributed to the increased open-circuit voltage (0.77±0.02 V) achieved by the increased Fermi energy levels of the working electrodes and the improved short-circuit current density (15.67±0.43 mA/cm2) by efficient electron transfer pathways. Therefore, optimized TiO2 BLs fabricated by USPD may allow performance improvements in DSSCs.

Abstract
 1. 서 론
 2. 실험 방법
 3. 결과 및 고찰
 4. 결 론
 감사의 글
 References

• 배주원(서울과학기술대학교 신소재공학과) | Ju-won Bae
• 구본율(서울과학기술대학교 의공학-바이오소재 융합 협동과정 신소재공학프로그램) | Bon-Ryul Koo
• 이태근(서울과학기술대학교 신소재공학과) | Tae-Kuen Lee Corresponding author
• 안효진(서울과학기술대학교 의공학-바이오소재 융합 협동과정 신소재공학프로그램) | Hyo-Jin Ahn Corresponding author