Towards 26% efficiency in inverted perovskite solar cells via interfacial flipped band bending and suppressed deep-level traps

Abstract

The strong nonradiative recombination loss of inverted PSCs at the surface and at the perovskite/C60 interface has limited the open-circuit voltage (Voc) and fill factor (FF) of the device and...

Hot‐Carrier Cooling Regulation for Mixed Sn‐Pb Perovskite Solar Cells

“…[12] Zheng et al took advantage of piperazinium diiodide as a surface passivation layer to suppress surface deep-level defects and adjust the band alignment at the interface, thereby improving the hot charge carrier extraction efficiency at the interface. [13] Dai et al introduced tin into lead-based perovskite to delay the relaxation process of hot charge carriers, and reduce defects and carrier recombination, thereby maintaining hot charge carriers and reducing the energy loss rate during the thermalization process. [7] The process of hot carrier cooling is primarily influenced by the densities of defects and trap states for low-light generated carriers, which in mixed Sn-Pb narrow-E g perovskite solar cells (PSCs) are attributed to defects generated during crystallization and Sn 2+ oxidation.…”

Unraveling the Influence of Solvent on Side Reactions between Formamidinium Lead Triiodide and Methylammonium Cations

“…It is one of the core issues restricting large-scale industrial production. , For example, formamidinium lead triiodide (FAPbI 3 ) perovskite materials, as the most widely used and effective components in PSCs, face a spontaneous transformation from the black cubic FAPbI 3 perovskite α-phase to the yellow hexagonal inactive 2H δ-phase at room temperature. , Fortunately, composition engineering with methylammonium iodide or bromide , or additive engineering with methylammonium chloride (MACl) can effectively suppress the phase transition of FAPbI 3 and increase the grain size, which thus improves the performance of the devices. Currently, single-junction PSCs with an efficiency greater than 26%, whether the n-i-p structure, , p-i-n structure, , one-step method, or two-step method, basically use MACl as an additive.…”

“…The deprotonation of MA + and subsequent chemical reactions constitute the primary causes of aging FAPbI 3 perovskite precursor solution. Recently, it has also been reported in the literature that MACl additives can react directly with FAPbI 3 perovskites to form MFAI byproducts during the heating process. − The impact of MFAI on the efficiency and stability of PSCs has attracted increasing attention. , …”

“…11,12 Fortunately, composition engineering with methylammonium iodide or bromide 13,14 or additive engineering 15 with methylammonium chloride (MACl) can effectively suppress the phase transition of FAPbI 3 and increase the grain size, 12 which thus improves the performance of the devices. Currently, single-junction PSCs with an efficiency greater than 26%, whether the n-i-p structure, 16,17 p-i-n structure, 18,19 one-step method, 17 or twostep method, 16 basically use MACl as an additive.…”

“…32−36 The impact of MFAI on the efficiency and stability of PSCs has attracted increasing attention. 18,37 Several factors affect the reactivity of FAPbI 3 perovskites in the presence of MA + cations. First, temperature is the most critical factor affecting the deprotonation of MA + ; higher temperatures promote the deprotonation of MA + .…”