2023年第70回応用物理学会春季学術講演会

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12 有機分子・バイオエレクトロニクス » 12.5 有機・ハイブリッド太陽電池

[18a-PB01-1~25] 12.5 有機・ハイブリッド太陽電池

2023年3月18日(土) 09:30 〜 11:30 PB01 (ポスター)

09:30 〜 11:30

[18a-PB01-15] The modification of the electron transporting layer for decreased loss in open-circuit voltage in terms of tin perovskite solar cells

Liu Jiaqi1、Liang Wang1、Qing Shen1、Shuzi Hayase1 (1.The University of Electro-Communications)

キーワード:perovskite, electron transporting layer

The extensive utilization of solar energy is the target of researchers in energy, physics, chemistry, etc. Perovskite solar cells (PSCs) have been one of the most prevalent solar cells in the world due to their low cost and fast development in efficiency. Even though the efficiency of PSCs has reached around 25.7%, the toxicity of lead-based PSCs is fatal. Therefore, a new type of lead-free PSCs has been established by substituting lead with tin. The tin-based PSCs have extra advantages, such as smaller bandgap values and high charge-carrier mobility, compared to lead-based PSCs. So far, the efficiency of tin-based PSCs has reached 14.3%, which is still far from the theoretical prediction. The deficiencies are the unsatisfied incident photon-to-electron conversion efficiency (IPCE) and the loss in open-circuit voltage. C60 has been widely used in the PSCs as an electron transporting layer (ETL). However, the open-circuit voltage seems to be a bottleneck that limits the overall efficiency. We investigated the band alignment between the hole transporting layer (HTL), perovskite, and ETL using the Kelvin probe and photoelectron yield spectroscopy. The proposed band alignment is illustrated in Figure 1. It shows that the band bending between perovskite and ETL is detrimental to electron transport due to the shallower Fermi level of perovskite than that of C60. It also limits the open-circuit voltage of the device. Therefore, the modification on the ETL was done to decrease the loss in the open-circuit voltage.