講演情報
[17p-K405-8]Surface composition control for reducing interfacial recombination in hole-transport-layer-free tin perovskite solar cells
〇Liu Jiaqi1, Huan Bi1, Liang Wang1, Qing Shen1, Shuzi Hayase1 (1.UEC)
キーワード：
perovskite
Tin-based perovskite solar cells (Sn PSCs) have attracted considerable attention as promising alternatives to their lead-based counterparts, owing to their lower toxicity and comparable photovoltaic performance. Recently, Sn PSCs have achieved power conversion efficiencies (PCEs) exceeding 16%.[1] However, many studies use ICBA as the electron transport layer (ETL), which consistently suffers from notable Jsc losses. Although C60 as the ETL is generally more favorable for carrier extraction, it tends to undergo recombination at the interface with Sn PSCs, leading to Voc losses. Hence, mitigating interface losses between the Sn perovskite and the ETL is crucial.
In this study, a SnI2 surface layer is formed via high-temperature annealing, during which the MAI component evaporates. This interface effectively reduces recombination between the conduction band of C60 and the valence band of the perovskite. We examined the quasi-Fermi level splitting (QFLS), which determines the open-circuit voltage (Voc) in solar cells. As shown in Figure 1b, the QFLS was calculated from the photoluminescence quantum yield (PLQY) of the Sn perovskite (bulk loss) and the perovskite/ETL interface (interface loss). Although bulk loss is greater at an annealing temperature of 100°C, this process significantly diminishes interfacial loss with the ETL. Consequently, the efficiency of Sn PSCs exceeds 11%, with a Voc surpassing 700 mV (Figure 1a).
In this study, a SnI2 surface layer is formed via high-temperature annealing, during which the MAI component evaporates. This interface effectively reduces recombination between the conduction band of C60 and the valence band of the perovskite. We examined the quasi-Fermi level splitting (QFLS), which determines the open-circuit voltage (Voc) in solar cells. As shown in Figure 1b, the QFLS was calculated from the photoluminescence quantum yield (PLQY) of the Sn perovskite (bulk loss) and the perovskite/ETL interface (interface loss). Although bulk loss is greater at an annealing temperature of 100°C, this process significantly diminishes interfacial loss with the ETL. Consequently, the efficiency of Sn PSCs exceeds 11%, with a Voc surpassing 700 mV (Figure 1a).