Research and application of TiO₂/AZO bilayer electron transport structure

TiO₂ films prepared by magnetron sputtering are investigated for their passivation effect on silicon wafers, along with the influence of post-annealing treatment on the passivation properties of TiO₂ films. Considering TiO₂ as an excellent electron transport material, this research explores the impact of thickness and post-annealing treatment on solar cells utilizing TiO₂ as an electron transport layer (ETL). Furthermore, a TiO₂/AZO bilayer electron transport layer is proposed and fabricated, enhancing carrier transport and extraction, thereby increasing the power conversion efficiency (PCE) of solar cells from 11.26% with TiO₂ alone as the ETL to 13.96% with the TiO₂/AZO bilayer ETL. The band structure is also analyzed to further investigate the internal carrier transport mechanism of the bilayer ETL.