Efficient flexible organic solar cells with a low-temperature-processed Al-doped zinc oxide electron transport layer
발표자
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초록
내용
Zinc oxide (ZnO) has been widely used in inverted organic solar cells (I-OSCs) as the electron transport layer (ETL) due to its excellent electrical properties. However, the high-temperature process (> 300 ℃) applied to the ZnO ETL to enhance its electrical properties has been regarded as the bottleneck for application of this ETL to flexible I-OSCs due to the limited temperature tolerance of flexible substrates. In this work, we synthesized aluminum (Al)-doped ZnO with a sol-gel process (AZO) and successfully demonstrated highly efficient flexible I-OSCs with a low-temperature-processed (140 ℃) AZO ETL (AZO 140 ℃). Since Al doping of ZnO results in an enhanced electrical conductivity and reduced defects in ZnO even for low-temperature-treated materials, the rigid and flexible I-OSCs with AZO 140 ℃ ETLs exhibit power conversion efficiencies (PCEs) of 16.3 and 14.4%, respectively, which are higher than those of I-OSCs with low-temperature-processed (140 ℃) ZnO ETLs.