Improved Performance and Stability of Perovskite Solar Modules by Regulating Interfacial Ion Diffusion with Nonionic Cross‐Linked 1D Lead‐Iodide

Abstract

The power conversion efficiency (PCE) of PSCs has jumped from 3.8% to 25.5% in the last decade, which was close to commercial solar cells. [3] However, achieving long-term stability under actual operating conditions is challenging for PSCs [4] and perovskite solar cell modules (PSMs). [5] Typically, 3D hybrid perovskites materials are self-assembled between smaller monovalent cation and corner-sharing [PbX 6 ] 4− octahedral frameworks via intrinsically weak hydrogen bonding, indicating a considerable concentration of mobile ions which is thermodynamically unavoidable in perovskites due to their low formation energies and high diffusion coefficients. [6] These interfacial ion diffusion processes can be further accelerated in photovoltaic devices by moisture, thermal, illumination, and electric field. [4c] Especially, the large-scale PSMs suffered from more complex interfacial ion diffusion channels than that of the small area devices, resulting in a more serious stability predicament on the module scale. [7] In order to overcome this issue, exploiting the superior stability of low-dimensional (LD) perovskite materials has been widely reported as passivators in perovskite photovoltaic devices. [8] The hydrophobicity of their large organic cations in LD perovskite could suppress ion diffusion and slow photodecomposition by minimizing vacancy migration and accumulation. [9] Many researchers have shown that LD perovskite has great intelligence for enhancing photostability by mixed 1D/3D or 2D/3D perovskite structures. [10] For example, Chen et al. employed propargyllammonium (PA + ) at the 3D perovskite/ spiro-OMeTAD interface to form the cross-linked 1D perovskitoid with excess PbI 2 . The corresponding 1D/3D perovskite heterostructure devices exhibited a PCE of 21.19% with >3000 h of operating condition stability. [10d] Nevertheless, even in the LD perovskites as mentioned above, instability induced by the intrinsic ionic properties still exists. [11] Therefore, it is highly desired to develop interface passivation and buffer layer materials for realizing long-term operational stability of high-efficiency PSMs.As one of the perovskite components, lead-halide itself can also form a variety of neutral LD materials Pb(L)X 2 (X = halide, Long-term stability has become the major obstacle for the successful large-scale application of perovskites devices. Owing to the ionic nature of metal-halide perovskites, the interfacial ion diffusion can induce irreversible degradation under operational conditions, which presents a great challenge to realize stable perovskite solar modules. Here, a diphenylphosphine oxide compound, ethane-1,2-diylbis(diphenylphosphine oxide) (DPPO) is introduced to coordinate with lead iodide and form a cross-linked 1D Pb 3 I 6 -DPPO (1D-PbI 2 ) complex. These judiciously designed cross-linked nonionic low-dimensional lead halide/organic adducts can passivate the defects of perovskite while acting as a robust ion diffusion barrier, thus significantly improving the electronic quality and intrinsi...

Interfacial Defect Passivation Effect of N-Methyl-N-(thien-2-ylmethyl)amine for Highly Effective Perovskite Solar Cells

“…We prepared a hole-only device ITO/PEDOT:PSS/perovskite/spiro-OMeTAD/Au and measured the dark current in Figure e,f. The V TFL of the NMTMA-modified sample decreased from 0.298 V of the pristine one to 0.211 V, and the n trap value reduced from 1.69 × 10 17 to 1.20 × 10 17 cm –3 , indicating that NMTMA can enhance the quality of perovskite films, significantly passivate defects, and decrease nonradiative recombination …”

“…The V TFL of the NMTMA- modified sample decreased from 0.298 V of the pristine one to 0.211 V, and the n trap value reduced from 1.69 × 10 17 to 1.20 × 10 17 cm −3 , indicating that NMTMA can enhance the quality of perovskite films, significantly passivate defects, and decrease nonradiative recombination. 54 The C−V curve of the pristine and NMTMA-modified PSCs was measured and is shown in Figure 5a. The capacitance value of the NMTMA-modified sample was smaller than that of the pristine sample under the same bias voltage.…”

Highly Orientational Order Perovskite Induced by In situ‐generated 1D Perovskitoid for Efficient and Stable Printable Photovoltaics

“…[27] Most recently, Li et al introduced ethane-1,2-diylbis(diphenylphosphine oxide) (DPPO) to form a crosslinked nonionic 1D Pb 3 I 6 DPPO compound, which can passivate the defects of perovskite and act as a robust ion diffusion barrier, the electronic quality and intrinsic stability of perovskite films were also improved. [28] Another challenge for PSCs is transferring the laboratoryscale devices to large-scale modules, which is required to reduce the cost of generating power production cost. Inkjet printing [29,30] and screen printing [31] are effective methods to pattern the materials.…”

Tailoring Two-Dimensional Ruddlesden–Popper Perovskite via 1D Perovskitoid Enables Efficient and Stable Solar Cells

“…1D perovskitoid has been widely employed in 3D perovskite to improve stability and PCE of the PSCs, 36,37 such as cross-linked 1D Pb 3 I 6 DPPO and 1D BnPbI 3 . 38,39 In addition, there is a high lattice match between 1D perovskitoid and conventional perovskite materials, 40 which makes it one kind of ideal material to regulate the properties of perovskite materials. Besides, 1D perovskitoid is favorable for charge transfer.…”

“…As another low dimension material, 1D perovskitoid materials employed guiding channels for transportation and propagation of charge carriers and photons, accompanied by stable property due to the large exciton binding energy and wide bandgap. 1D perovskitoid has been widely employed in 3D perovskite to improve stability and PCE of the PSCs, , such as cross-linked 1D Pb 3 I 6 DPPO and 1D BnPbI 3 . , In addition, there is a high lattice match between 1D perovskitoid and conventional perovskite materials, which makes it one kind of ideal material to regulate the properties of perovskite materials. Besides, 1D perovskitoid is favorable for charge transfer .…”