Wide bandgap (WBG) Sn perovskite solar cells (PSCs) efficiency enhancement is another sought after field and to resolve the issues related to fast crystallization, trap density and moisture induced oxidation of Sn²⁺ state in Sn perovskite, we endeavor the benefits of substituting hydrophobic phenylethlammonium (PEA⁺) cation into WBG PEA_xFA_0.75MA_0.25-xSnI₂Br through compositional engineering. We have realized that PEA⁺ substitution in WBG Sn perovskite led to form 2D/3D mixed perovskite and execute preferential orientation of 3D perovskite planes with controlled crystallinity. Our observation suggests that 2D perovskite phase here helps in merging the grain boundaries and reduce the rate of moisture penetration which ultimately controlled further oxidation of Sn²⁺. Also, the substitution of PEA⁺ in WBG Sn perovskite helps in modulating the band energies and aids to efficient electron injection from perovskite to transport layer. Compared to the 3D counterpart, 2D/3D perovskite exhibits slow lifetime decay (τ_avg = 1.25 ns), suppressed trap state density (1.7 × 10¹⁶ cm⁻³), improved band alignment with slower carrier recombination (τ = 1217 μs) and efficient charge extraction. As compared to FASnI₂Br (PCE of 2.38%) and FA_0.75MA_0.25SnI₂Br (PCE of 3.66%), our champion device PCE of 7.96% (Certified PCE of 7.84%) with J_sc of 16.89 mA·cm⁻², V_oc of 0.67 V and FF of 70.36% was achieved for PEA_0.15FA_0.75MA_0.10SnI₂Br, which is the highest PCE till date with compositional engineering strategy. The device kept under N₂ atmosphere retained nearly original PCE after almost 1500 hrs and air stability of 300 hrs without encapsulation, indicating excellent stability.

宽带隙 (WBG) Sn 钙钛矿太阳能电池 (PSC) 效率增强是另一个备受追捧的领域，为了解决与 Sn 钙钛矿中 Sn ²⁺态的快速结晶、陷阱密度和水分诱导氧化相关的问题，我们努力利用替代的好处通过组成工程将疏水性苯乙铵 (PEA ⁺ ) 阳离子转化为 WBG PEA _x FA _0.75 MA _0.25-x SnI ₂ Br。我们已经意识到 PEA ⁺WBG Sn 钙钛矿中的取代导致形成 2D/3D 混合钙钛矿并执行具有受控结晶度的 3D 钙钛矿平面的优先取向。我们的观察表明，此处的二维钙钛矿相有助于合并晶界并降低水分渗透率，从而最终控制 Sn ²⁺的进一步氧化。此外，WBG Sn 钙钛矿中 PEA ⁺的替代有助于调节带能并有助于从钙钛矿到传输层的有效电子注入。与 3D 对应物相比，2D/3D 钙钛矿表现出缓慢的寿命衰减（τ _avg  = 1.25 ns），抑制陷阱态密度（1.7 × 10 ¹⁶ cm ^-3），通过较慢的载流子复合（τ = 1217 μs）和有效的电荷提取改善了能带对齐。与 FASnI ₂ Br（PCE 为 2.38%）和 FA _0.75 MA _0.25 SnI ₂ Br（PCE 为 3.66%）相比，我们的冠军器件 PCE 为 7.96%（认证 PCE 为 7.84%），J _sc为 16.89 mA·cm ^{-如图2所示，PEA} _0.15 FA _0.75 MA _0.10 SnI ₂ Br 的V _oc为0.67 V，FF 为70.36% ，这是迄今为止采用组合工程策略的最高PCE。设备保持在 N _2以下大气在几乎 1500 小时后保持几乎原始的 PCE，在没有封装的情况下保持 300 小时的空气稳定性，表明稳定性极佳。