Review on the Application of SnO₂ in Perovskite Solar Cells

Abstract

SnO 2 has been well investigated in many successful state-of-the-art perovskite solar cells (PSCs) due to its favorable attributes such as high mobility, wide bandgap, and deep conduction band and valence band. Several independent studies show the performances of PSCs with SnO 2 are higher than that with TiO 2 , especially in device stability. In 2015, the first planar PSCs were reported with a power conversion efficiency over 17% using a low temperature sol-derived SnO 2 nanocrystal electron transport layer (ETL). Since then, many other groups have also reported high performance PSCs based on SnO 2 ETLs. SnO 2 planar PSCs show currently the highest performance in planar configuration devices (21.6%) and are close to the record holder of TiO 2 mesoporous PSCs, suggesting their high potential as ETLs in PSCs. The main concerns with the application of SnO 2 as ETL are that it suffers from degradation in high temperature processes and that its much lower conduction band compared to perovskite may result in a voltage loss of PSCs. Here, notable achievements to date are outlined, the unique attributes of SnO 2 as ETLs in PSCs are described, and the challenges facing the successful development of PSCs and approaches to the problems are discussed.

Review of Recent Progress in Antimony Chalcogenide‐Based Solar Cells: Materials and Devices

“…It's noted that Sb 2 Se 3 solar cells using an high‐temperature solution processed SnO 2 as an ETL delivered low efficiency compared with those of CdS and ZnO ETLs . Based on our understanding of SnO 2 from previous review papers, we believe the reason for this low efficiency is that high‐temperature processed SnO 2 ETL cannot effectively block holes compared with the low‐temperature processed ETLs, leading to severe interface recombination and shunt paths. For hole extraction, inorganic materials such as NiO, V 2 O 5 , and CuSCN have also been incorporated in solar cells to transport holes.…”

A Purified, Solvent‐Intercalated Precursor Complex for Wide‐Process‐Window Fabrication of Efficient Perovskite Solar Cells and Modules

“…Thee lectron-transport layer was SnO 2 , [40,41] and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) was used as the hole-transport material. Thee lectron-transport layer was SnO 2 , [40,41] and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) was used as the hole-transport material.…”

Anti‐Oxidizing Radical Polymer‐Incorporated Perovskite Layers and their Photovoltaic Characteristics in Solar Cells

“…The decomposition of the organo‐lead halide perovskite compounds with oxygen on the surface of m‐TiO 2 under light irradiation was studied as an oxygen‐triggered decomposition of the perovskite layer and is ascribed to the reaction of O 2 .− on the surface of the perovskite grains . Although m‐TiO 2 ‐free cells, such as the cells using planar tin oxide (SnO 2 ) as an effective electron‐transporting underlayer, have been recently studied as improved‐efficiency cells, the oxygen‐triggered degradation of perovskites remains crucial in these cells . Although the use of hole‐transporting polymers as an oxygen barrier layer and/or an encapsulation of whole devices have been reported to retard the decomposition of perovskites with oxygen and to guarantee cell durability, they are not essential …”

“…[26] Althoughm -TiO 2 -free cells, such as the cellsu sing planar tin oxide (SnO 2 )a sa ne ffective electron-transporting underlayer, have been recently studied asi mproved-efficiency cells, the oxygen-triggered degradation of perovskites remains crucial in these cells. [27][28][29][30] Althought he use of hole-transporting polymers as an oxygen barrier layer and/ora ne ncapsulationo f whole devices have been reported to retard the decomposition of perovskites with oxygen and to guarantee cell durability,they are not essential. [31,32] An incorporation of asmall amount of polymers as ascaffold for the formation of high-quality perovskite crystals has been also studied.…”