Interface Engineering via Amino Acid for Efficient and Stable Perovskite Solar Cells

Abstract

PCE of PSCs has not yet reached its limit (30.5%), implying there is still much room for further improve the performance of PSCs.To obtain PSCs with higher photoelectric performance and higher stability, various strategies have been developed to optimize the perovskite layer and charge carrier transport layers. [10][11][12] Exploring appropriate materials as efficient electron transport layers (ETLs) is also vital to promote the rapid development of PSCs. Titanium dioxide (TiO 2 ) was initially used as ETL material in PSCs, owing to the advantages of low cost, high stability, and superior ability able to effectively transferring of electrons from the perovskite layer to the bottom electrode. However, the energy levels of TiO 2 and perovskite are not matched well. Meanwhile and the annealing temperature of TiO 2 is high (above 450 °C), which is energy consuming and incompatible with flexible devices. [13][14][15] Alternatively, tin dioxide (SnO 2 ), has become the most commonly used ETL material, due to its advantages of low-temperature manufacturing, good energy level matching, and high electron mobility. However, using SnO 2 as ETL is inevitable to encounter defects (oxygen vacancy defects) pinholes at the film surface. These defects have a significantly negative impact on the photovoltaic performance and stability performance of perovskite solar cells. [16,17] Based on this, interfacial modification and doping strategies were applied to PSCs. Ogomi et al. introduced a monolayer HOCO-R-NH 3

Application of Natural Molecules in Efficient and Stable Perovskite Solar Cells

“…However, the inevitable surface defects and pinholes of the film significantly deteriorate the photovoltaic performance of PSCs. To overcome these shortages, Geng and co-authors employed L-aspartic acid (LAA) as the interlayer between ETL and perovskite [ 39 ]. As shown in Figure 2 b, with the treatment of LAA, the carboxyl group interacts with uncoordinated Sn 4+ and neutralizes the alkalinity of the hydroxyl group in SnO 2 , leading to a denser and smoother ETL layer with reduced defects, and negligible transmittance loss, and enhanced conductivity.…”

“…Copyright 2019, Elsevier. ( b ) Passivation mechanism of LAA at the SnO 2 ETL/PVK interface [ 39 ]. Copyright 2020, Wiley-VCH.…”

Regulating the Interplay at the Buried Interface for Efficient and Stable Carbon-Based CsPbI2Br Perovskite Solar Cells

“…Ammonium salts including NH 4 Cl and NH 4 F are also developed to improve electron mobility, tune the work function ( W F ), and passivate the surface defects of SnO 2 . , Unfortunately, these materials, which may be able to further optimize perovskite films, are easy to volatilize into the ambient atmosphere during annealing. In contrast, small molecule materials with carboxyl and amine groups have been explored to simultaneously passivate the defects of SnO 2 and perovskite films by donating a lone pair of electrons . Nevertheless, there are few reports on modifying the SnO 2 /CsPbI 2 Br buried interface by simultaneously achieving the above functions.…”

“…In contrast, small molecule materials with carboxyl and amine groups have been explored to simultaneously passivate the defects of SnO 2 and perovskite films by donating a lone pair of electrons. 22 Nevertheless, there are few reports on modifying the SnO 2 /CsPbI 2 Br buried interface by simultaneously achieving the above functions.…”

Eco-Friendly Boost for Perovskite Photovoltaics: Harnessing Cellulose-Modified SnO2 as a High-Performance Electron Transporting Material

“…Through a comprehensive investigation of the performance, stability, and operational dynamics of SnO 2 -based PSCs, the studies strive to contribute to a broader understanding of novel strategies for enhancing the efficacy and durability of devices. Recent efforts have been directed toward investigating the viability of SnO 2 as an ETL in PSCs, encompassing various approaches such as mesoscopic structures, , interface engineering, − and doping strategies. − …”