Hyperstable Perovskite Solar Cells Without Ion Migration and Metal Diffusion Based on ZnS Segregated Cubic ZnTiO₃ Electron Transport Layers

Abstract

Perovskite solar cells (PSCs) have attracted great interest in recent decade, however, stability issue and large‐scale application still remain as roadblocks to their practical applications. To settle aforementioned issues, metal diffusion and ion migration should be controlled to improve long‐term operational stability. Herein, cubic zinc metatitanate (ZTO) is optimized and improved by segregating with surface sulfidation. The sulfurized electron transporting layer, label as ZTO‐ZnS, based PSCs achieved an amazing power conversion efficiency (PCE) of 21.3%. A large‐area module (8.0 cm2 active area) based on ZTO‐ZnS is also developed with 15.9% PCE. Furthermore, combining with inorganic CuI hole transporting layer and carbon counter electrode, metal diffusion, and ion migration effect are eliminated drastically in ZTO‐ZnS‐based PSCs. The combined PSC devices can easily keep more than 85% initial PCE after 1 000 h at 85 °C in air with a relative humidity of 85% under maximum power point and continuous AM 1.5G illumination. The persistence in stability is investigated and revealed fully by energy dispersive spectrometer analysis, attributing to the PSC structure which blocks the metal diffusion and ion migration in the devices. A big step forward industrialization and commercialization for PSCs is made.

85 °C/85%‐Stable n‐i‐p Perovskite Photovoltaics with NiOx Hole Transport Layers Promoted By Perovskite Quantum Dots

“…Device Fabrication: 0.12-cm 2 perovskite solar cell: First, ZnTiO 3 (ZTO) electron transport layer was deposited on clean and patterned 2 × 2 cm 2 FTO by spray coating the mixture solution of Zn(OAc) 2 (2.5 mL, 0.2 m in ethanol, Sinopharm), titanium diisopropoxide bis(acetylacetonate) (0.5 mL, 75% in isopropanol, Alfa Aesar), and thiourea (4.7 mg) in ethanol (50 mL) at 450 °C for 30 min, as reported in our previous work. [26] Then, perovskite films with different compositions were deposited by spin-coating methods. FA 0.85 MA 0.15 PbI 2.55 Br 0.45 : A solution of 900 mg FAPbI 3 , 22.5 mg MAPbBr 3 , 65 mg PbI 2 , 33 mg MACl dissolved in 1 mL DMF/DMSO (4/1) was spun at 1200 rpm for 5 s followed by 6000 rpm for 20 s, with diethyl ether sprayed at 5 s prior the end of the process.…”

Encapsulation and Stability Testing of Perovskite Solar Cells for Real Life Applications

“…Various polymers have been reported for the encapsulation of perovskite films and devices, such as PDMS, plasma polymer film from adamantane precursor, poly­(methylmethacrylate) (PMMA), ,− parylene C, TPU, PMMA/vulcanized silicone rubber, PMMA//styrene-butadiene (SB), fluoropolymer coating, etc. In addition to polymer films, roll-transferred graphene has also been used as well as spray-coated reduced graphene oxide (rGO) . Furthermore, other materials, such as hBN flakes and polycarbonate, have been used for encapsulation of perovskite materials, but they have not been common in devices.…”

“…For example, polymer layer-encapsulated PSC stability has typically been tested under mild conditions, such as ambient storage. ,, When damp heat testing is reported, it is typically performed for a short time, such as 1 and 100 h . An exception is fluoropolymer coating (on top of the perovskite and back surface of the glass), where the devices were subject to outdoor testing in addition to exposure to high humidity (95%) environments, and ∼500 nm thick spray-coated reduced graphene oxide (rGO) film encapsulation, where the devices were subjected to damp heat testing . The situation is similar for inorganic thin film encapsulation, where the majority of reports show stability for ambient storage with some exceptions reporting nonstandard accelerated aging conditions (shelf life at 50 °C, 50% RH) and rarely considering harsh testing conditions, such as damp heat 85 °C, 85%RH and outdoor testing .…”

“…Nevertheless, it is likely that thin film encapsulation combined with the cover glass/cover sheet encapsulation , can yield significantly improved performance. Out of the materials reported, the most promising ones when taking into account performance as well as the simplicity and low cost of the deposition are fluoropolymers and spray coated rGO . However, in the case of rGO, one possible problem is that the encapsulating film is expected to have low electrical resistance.…”

Governing PbI6octahedral frameworks for high-stability perovskite solar modules

“…1d) were elaborately selected, using ZnTiO 3 -ZnS as the ETL to form band alignment and stable Zn-S-Pb coherent interlayer to promote ETL-perovskite interaction, and using the relatively stable FACsPbI 3 component as the perovskite layer. 24,34 The VT solution in isopropanol was optimized to be the concentration of 0.03 mg mL À1 , and the dose of 15 mL for each 2 Â 2 cm 2 perovskite film (Fig. S7a and Table S1, ESI †).…”