Extending the Photovoltaic Response of Perovskite Solar Cells into the Near‐Infrared with a Narrow‐Bandgap Organic Semiconductor
Extending the Photovoltaic Response of Perovskite Solar Cells into the Near‐Infrared with a Narrow‐Bandgap Organic Semiconductor
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DOI：
10.1002/adma.201904494
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发表时间：
2019-09
影响因子：
29.4
通讯作者：
Xiaoming Zhao;Chao Yao;Tianran Liu;J. Hamill;G. N. Ngongang Ndjawa;G. Cheng;N. Yao;H. Meng;Y. Loo
中科院分区：
文献类型：
--
作者：
Xiaoming Zhao;Chao Yao;Tianran Liu;J. Hamill;G. N. Ngongang Ndjawa;G. Cheng;N. Yao;H. Meng;Y. Loo
典型的铅基钙钛矿太阳能电池在800 nm左右开始产生光，在近红外（NIR）中留下大量光谱损失。将800 nm以上的光吸收扩展到NIR中应该会增加光电流的产生，并进一步提高钙钛矿太阳能电池（PSC）的光伏效率。在这里，报道了一种简单而容易的方法，将NIR发色团（也是刘易斯碱）掺入钙钛矿吸收剂中，以拓宽其光响应并提高其光伏效率。与没有这种有机发色团的原始PSC相比，这些太阳能电池仅在钙钛矿活性层的带边之外的NIR中产生光电流。考虑到有机半导体的刘易斯-碱性性质，将其添加到光活性层中也有效地钝化钙钛矿缺陷。因此，这些膜表现出显著降低的陷阱密度、增强的空穴和电子迁移率以及抑制的照明诱导的离子迁移。因此，具有有机发色团的钙钛矿太阳能电池表现出21.6%的效率提高，并且在连续一个太阳照射下的操作稳定性大幅提高。结果表明，直接引入多功能有机半导体的潜在普遍性，该多功能有机半导体既扩展了光吸收又钝化了钙钛矿活性层中的表面陷阱，以产生高效且稳定的NIR-收获PSC。
Typical lead‐based perovskites solar cells show an onset of photogeneration around 800 nm, leaving plenty of spectral loss in the near‐infrared (NIR). Extending light absorption beyond 800 nm into the NIR should increase photocurrent generation and further improve photovoltaic efficiency of perovskite solar cells (PSCs). Here, a simple and facile approach is reported to incorporate a NIR‐chromophore that is also a Lewis‐base into perovskite absorbers to broaden their photoresponse and increase their photovoltaic efficiency. Compared with pristine PSCs without such an organic chromophore, these solar cells generate photocurrent in the NIR beyond the band edge of the perovskite active layer alone. Given the Lewis‐basic nature of the organic semiconductor, its addition to the photoactive layer also effectively passivates perovskite defects. These films thus exhibit significantly reduced trap densities, enhanced hole and electron mobilities, and suppressed illumination‐induced ion migration. As a consequence, perovskite solar cells with organic chromophore exhibit an enhanced efficiency of 21.6%, and substantively improved operational stability under continuous one‐sun illumination. The results demonstrate the potential generalizability of directly incorporating a multifunctional organic semiconductor that both extends light absorption and passivates surface traps in perovskite active layers to yield highly efficient and stable NIR‐harvesting PSCs.