Dual-site passivation of tin-related defects enabling efficient lead-free tin perovskite solar cells

An Overview of Lead, Tin, and Mixed Tin–Lead‐Based ABI3 Perovskite Solar Cells

“…a) Record PCE values reported for Pb‐based PeSCs made of single cation reported over the year: MA, [3b,15,200] FA, [ 122,201 ] and Cs. [ 195,202 ] b) Record PCEs of Sn‐based PeSCs: MA, [ 68,203 ] FA, [82b,109,112,113,204] and Cs. [ 82a,84 − 86,205 ] c) Record PCEs of Sn–Pb‐based PeSCs made of different cation compositions.…”

“…[ 112 ] In addition, a following research incorporated 1 mol% ethylenediammonium dibromide (EDABr 2 ) instead of EDAI 2 and achieved a PCE of 14.23% in 2022 (Figure 6c). [ 113 ] The EDABr 2 was demonstrated to possess better capability on passivation of deep‐level defects due to the synergetic roles EDA 2+ cation and Br − anion.…”

“…c) Reproduced with permission. [ 113 ] Copyright 2022, Elsevier Ltd. d) Adapted with permission [128b] . Copyright 2022, Wiley‐VCH.…”

All‐Inorganic Perovskite‐Based Monolithic Perovskite/Organic Tandem Solar Cells with 23.21% Efficiency by Dual‐Interface Engineering

“…As depicted in Figure 2 a, for MAFm molecule, the electron‐donor zones are mainly located around H, C, and N atoms of the MA + functional group, and O atoms of the Fm − functional group are responsible for the electron‐withdrawing area, suggesting that Fm − is the most possible sites that can interact with perovskites. [ 34 ] Furthermore, electronic structure calculations based on density functional theory (DFT) calculation are conducted to study the chemical interaction and passivation mechanisms at the CsPbI 2 Br/MAFm interfaces. As shown in Figure 2b, the I vacancy ( V I ) induced Pb–Pb dimer defects of CsPbI 2 Br (001) surface are the domain trap centers, [ 35 ] which causes severe localized electron wavefunction at the surface, while the introduction of MAFm is aimed to mitigate electron localization in the perovskite lattice by forming the PbFm bond (Figure 2c).…”

Remarkable Stability and Optoelectronic Properties of an All-Inorganic CsSn0.5Ge0.5I3 Perovskite Solar Cell

“…However, the toxicity caused by lead has always pushed people to seek lead-free perovskites considering environment-friendly applications. Many researchers investigate a lot of low-toxic or nontoxic inorganic perovskite materials, , so Ca­(II), Bi­(III), Sr­(II), Sn­(II), and Ge­(II) cations were used to replace Pb cations. − Among them, Sn-based perovskites have the potentially ideal electronic and optical properties that are even better than those of Pb-based perovskite due to its band gap close to the optimal one (≈1.3 eV), strong light absorption, and good carrier mobility. − In addition, the controllability of Sn content in CsSnI 3 enables it to be used not only as a light-absorbing layer but also as a hole transport material for lead-free perovskite solar cells. ,− However, the thermal instability and thermodynamically favorable antisite defect Sn I are the main reasons limiting the PCE of inorganic Sn-based perovskites. − Compared with inorganic Pb/Sn-based perovskites, Ge-based perovskites show different structural and electronic properties, especially its defect physics: the antisite defects will not dominate during fabrication. , Under Ge-rich/I-rich conditions, the formation energies of Ge and I vacancies are relatively low and CsGeI 3 is a p-type direct band gap semiconductor . But unfortunately, the I vacancy in CsGeI 3 is a deep electron trap under I-poor conditions, which obviously limits electron migration, thereby affecting the V OC of PSC. , In order to improve the photovoltaic performance of inorganic perovskite devices, researchers performed Sn and Ge hybridization to obtain a CsSn 0.5 Ge 0.5 I 3 perovskite, a promising lead-free light-absorbing material (LAM).…”