Suppressing Disproportionation Decomposition in Sn-Based Perovskite Light-Emitting Diodes

Abstract

Nontoxic Sn-based perovskite light-emitting diodes (Pero-LEDs) have been developing rapidly in recent years. However, high-quality Sn-based perovskite films are hardly prepared because of the heavy self-doping of Sn4+ in the as-prepared films. Most previous reports indicate that the Sn4+ formation is mainly attributed to the Sn2+ oxidation by external oxidizers. Here, for the first time, we reveal that the disproportionation decomposition of Sn2+ during the annealing process plays a critical role in degrading device performance. To resolve this issue, we introduced formamidine thiocyanate into the perovskite precursor as a thermal-sacrificial agent to alleviate the disproportionation decomposition. Finally, we achieved efficient Pero-LEDs with a maximum external quantum efficiency of 5.3% and ultralow efficiency roll-off. This work provides a view of understanding the instability of Sn-based perovskite and presents a practical method to achieve efficient Sn-based Pero-LEDs by suppressing the disproportionation decomposition of Sn2+.

Color‐Stable Two‐Dimensional Tin‐Based Perovskite Light‐Emitting Diodes: Passivation Effects of Diphenylphosphine Oxide Derivatives

“…efficiencies (EQEs) over 20%, [7][8][9][10][11][12][13][14][15][16][17] the device performance of Sn-based PeLEDs is still in an earlier stage with maximum EQEs <6%. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] The performance gap between Sn-based and Pb-based perovskites has been ascribed to the trap-limited nonradiative recombination due to their inherent high-density defect states. [34] These traps are usually induced by the prone oxidation of Sn 2+ to Sn 4+ , and faster crystallization process of Sn-based perovskites than Pb analogs.…”

Li, Na, K, Mg, Zn, Al, and Ca Anode Interface Chemistries Developed by Solid‐State Electrolytes

“…[ 375–378 ] NASICON‐type Li 1+x Al x Ti 2−x (PO 4 ) 3 ‐based Li–S batteries demonstrate both the chemical and electrochemical compatibilities influencing the Li‐S chemistries by reduction of Ti 4+ to Ti 3+ for 2.4 V versus Li/Li + by polysulfide species. [ 379,380 ] Further, replacing different SEs such as Li 1+x Al x Ge 2−x (PO 4 ) 3 , garnet, LGPS, Li 2 S‐P 2 S 5 ‐P 2 O 5 , Li x La 2/3‐x/3 TiO 3 , Li 1+x Y x Zr 2−x (PO 4 ) 3 , LiPON, Li 7 La 3 Zr 2 O 12 –PEO–LiClO 4 , Li 6 PS 5 Cl, PEO–LiTFSI, PEO–LiCF 3 SO 3 , and PEO–LiClO 4 , and LLZO SEs could improve the compatibility concerns. In contrast, operational cycle life and capacity fading are not reasonable.…”

“…In contrast, operational cycle life and capacity fading are not reasonable. [ 379–389 ] To improve Li interface structures with SEs, different Li‐alloys ( Figure ) have been reported, such as Li–In, Li–Sn, Li–Al, Li–Mg, etc. [ 390–393 ]…”

“…[375][376][377][378] NASICONtype Li 1+x Al x Ti 2−x (PO 4 ) 3 -based Li-S batteries demonstrate both the chemical and electrochemical compatibilities influencing the Li-S chemistries by reduction of Ti 4+ to Ti 3+ for 2.4 V versus Li/Li + by polysulfide species. [379,380] In contrast, operational cycle life and capacity fading are not reasonable. [379][380][381][382][383][384][385][386][387][388][389] To improve Li interface structures with SEs, different Li-alloys (Figure 16) have been reported, such as Li-In, Li-Sn, Li-Al, Li-Mg, etc.…”

Spectral Downshifting and Passivation Effects Using 2D Perovskite (OAm)2SnBr4 Films to Enhance the Properties of Si Nanowire Solar Cells

“…There is a great potential toward replacing Pb with Sn in perovskite materials, a step toward overcoming the toxicity of Pb ions. However, the stability of Sn 2+ is still under concern. , Recently, two-dimensional (2D) layered tin-halide perovskites have attracted the attention of researchers owing to their distinct optical and electronic properties, such as high quantum yield, large Stokes shift, and high carrier mobility, − which make these materials potential candidates in spectral downshifting. In contrast to their 3D counterparts, the organic Ruddlesden-Popper 2D perovskites comprise various organic spacers with long cationic chains that are hydrophobic, inhibiting moisture and oxygen ingress and improving stability by encapsulating the octahedron layers and passivating Sn sites. , Different 2D tin-halide perovskites had been synthesized in recent years with different techniques.…”