Self‐Repairing Tin‐Based Perovskite Solar Cells with a Breakthrough Efficiency Over 11%

Abstract

The development of tin (Sn)‐based perovskite solar cells (PSCs) is hindered by their lower power conversion efficiency and poorer stability compared to the lead‐based ones, which arise from the easy oxidation of Sn2+ to Sn4+. Herein, phenylhydrazine hydrochloride (PHCl) is introduced into FASnI3 (FA = NH2CH  NH2+) perovskite films to reduce the existing Sn4+ and prevent the further degradation of FASnI3, since PHCl has a reductive hydrazino group and a hydrophobic phenyl group. Consequently, the device achieves a record power conversion efficiency of 11.4% for lead‐free PSCs. Besides, the unencapsulated device displays almost no efficiency reduction in a glove box over 110 days and shows efficiency recovery after being exposed to air, due to a proposed self‐repairing trap state passivation process.

Solution-processed ITO nanoparticles as hole-selective electrodes for mesoscopic lead-free perovskite solar cells

“…Note that the back-contact electrodes of these regular planar or mesoscopic devices were made by thermal evaporation of silver metal under high vacuum condition that is limited to their future industrial scalability. While the planar devices adopt ~200 nm thickness, closely associated with the effective charge diffusion length, for high-performance tin perovskites in solar cells, 14,15,27,28,[32][33][34]41 the 1 μm thick Al 2 O 3 insulating film in the mesoscopic devices is too harsh in terms of effective charge carrier diffusion for the tin perovskites. The further improvement in PCE is likely made by decreasing the Al 2 O 3 thickness.…”

“…9 Such tin-based perovskites have been extended to other applications such as transistors, 10 photodetectors, 11 light-emitting diodes 12 and lasers. 13 For highperformance PSC, tin perovskites have evolved on suppressing oxidation of tin (from Sn 2+ to Sn 4+ ), pinholes and surface defects while improving crystallinity through an exploration of hybrid cations or anions, [14][15][16][17][18][19][20][21][22][23] additives [24][25][26][27][28][29][30][31][32][33] and interfacial engineering. [34][35][36][37] The additive approach is effective regardless of the type of tin perovskite and its interfaces.…”

“…39,40 Despite that great promise, the best performance of carbon-based tin PSC resides at 4.22 %, 19 whereas the efficiency of planar tin PSC is aggressively evolving over 9 %. 14,15,27,28,[32][33][34]41 One reason is that carbon does not reflect visible light, unlike Au or Ag in planar PSC, 39 and suffers from poor hole selectivity because of rapid charge recombination, thereby limiting significantly this otherwise promising technology.…”

High‐Efficiency Tin Halide Perovskite Solar Cells: The Chemistry of Tin (II) Compounds and Their Interaction with Lewis Base Additives during Perovskite Film Formation

“…The resultant PSC showed an increased PCE up to 8.48%. [ 68 ] Recently, Huang et al [ 69 ] included phenylhydrazine hydrochloride (PHCl) in FASnI 3 films to passivate trap states and improve the stability of the respective PSCs. Time‐resolved photoluminescence (TRPL) and Mott–Schottky (M–S) analysis showed that the FASnI 3 film with 5.0% PHCl resulted in ≈3 times longer carrier lifetime and ≈3.5 times higher built‐in voltage than those of the control film without PHCl.…”

An Efficient Non-Toxic and Non-Corrosive Perovskite Solar Cell

“…S. Das et al, fabricated perovskite solar cell and obtained an average efficiency of 16.34% [15]. C. Wang et al, reported an efficiency of 11.4% from lead free PSC [16]. S. Abdelaziz et al, numerically modelled and calculated an efficiency of 14.03% from formamidinium tin based perovskite solar cell [17].…”