data and code for paper "Shallow Defects and Variable Photoluminescence Decay Times up to 280 µs in Triple-Cation Perovskites"

<p>data of the figures shown in main text and in the supporting information, as well as MATLAB scripts for steady-state and transient photoluminescence simulations in the paper "Shallow Defects and Variable Photoluminescence Decay Times up to 280 µs in Triple-Cation Perovskites".</p&gt

Doped Bilayer Tin(IV) Oxide Electron Transport Layer for High Open‐Circuit Voltage Planar Perovskite Solar Cells with Reduced Hysteresis

International audienc

Enhanced performance of planar perovskite solar cells by doping the SnO2 electron transport layer with guanidinium chloride

International audienceTin (IV) oxide is a highly promising electron transport layer (ETL) for lead halide perovskite solar cells due to its high conductivity, transparency, wide band gap, and the possibility of low-temperature processing. Nonetheless, charge carrier recombination processes at the SnO 2 /perovskite interface diminish the device performance. Here, we demonstrate that SnO 2 doping with guanidine hydrochloride (G-SnO 2 ) leads to efficient surface passivation and a larger band offset between the ETL and the perovskite layer, resulting in reduced voltage losses and faster electron transfer. Moreover, G-SnO 2 facilitates the growth of highly crystalline perovskite layers. Consequently, a power conversion efficiency of up to 23.48% and a high open-circuit voltage of 1.18 V are obtained in solar cells incorporating the G-SnO 2 ETL. These devices also exhibited negligible hysteresis and maintained more than 96% of their initial power conversion efficiency after 1250 h exposure to the air without encapsulation

Crack-free perovskite layers for high performance and reproducible devices via improved control of ambient conditions during fabrication

Highlights - Cracking film can be avoided in summer by regulating ambient temperature. - High-quality perovskite films without cracking was prepared with low defects. - The PCE was boosted from 13.51% to 18.46% at ambient temperature of 18 °C. - High-efficiency PSCs device can be prepared at high ambient temperature. - This method can boost the efficiency of PSCs in the case of film cracking. Abstract Organic-inorganic perovskite has shown one of the most rapid growths ever in photovoltaic history and achieved remarkable achievement with PCE of 22.1%. Since the first perovskite solar cells (PSCs) was reported in 2009, it always existed a problem that the performance of PSCs prepared in winter is much better than summer due to films cracking. In this article, we explored the reasons for this phenomenon and provided a corresponding solution. It was found that film cracking was a major contributor for losses of PSCs performance. By adjusting ambient temperature of operating environment, the film quality and device performance can be increased effectively. Result showed that mirror-like perovskite film surface without cracks can be prepared by control operating environment, and the power conversion efficiency was boosted from 13% to values more than 18% measured under standard solar conditions (AM 1.5G, 100 mW/cm2). Furthermore, this method exhibits good reproducibility. It is expected that by this effective approach and better understanding of the perovskite preparation process, high efficiency and reproducible PSCs device can be prepared

Bidirectional Anions Gathering Strategy Afford Efficient Mixed Pb-Sn Perovskite Solar Cells

Abstract Mixed lead-tin (Pb-Sn) perovskite solar cells (PSCs) possess low toxicity and adjustable bandgap for both single-junction and all-perovskite tandem solar cells. However, the performance of mixed Pb-Sn PSCs still lags behind the theoretical efficiency. The uncontrollable crystallization and the resulting structural defect are important reasons. Here, the bidirectional anions gathering strategy (BAG) is reported by using Methylammonium acetate (MAAc) and Methylammonium thiocyanate (MASCN) as perovskite bulk additives, which Ac− escapes from the perovskite film top surface while SCN− gathers at the perovskite film bottom in the crystallization process. After the optoelectronic techniques, the bidirectional anions movement caused by the top-down gradient crystallization is demonstrated. The layer-by-layer crystallization can collect anions in the next layer and gather at the broader, enabling a controllable crystallization process, thus getting a high-quality perovskite film with better phase crystallinity and lower defect concentration. As a result, PSCs treated by the BAG strategy exhibit outstanding photovoltaic and electroluminescent performance with a champion efficiency of 22.14%. Additionally, it demonstrates excellent long-term stability, which retains ≈92.8% of its initial efficiency after 4000 h aging test in the N2 glove box

Enhanced morphology and stability of high-performance perovskite solar cells with ultra-smooth surface and high fill factor via crystal growth engineering

Since solvent engineering methods were applied to the treatment of perovskite films, the performance of perovskite solar cells (PSCs) has shown rapid growth and remarkable achievements have been made. Here we report a highly reproducible method for controlling perovskite crystal growth by a spraying anti-solvent process, which is quite different from conventional dripping methods. The results showed that the change of the method by which the anti-solvent is used has a significant impact on the morphology and formation of the perovskite. It has a high probability to form a mirror-like surface without wave-circle or ring defects, and to obtain a longer carrier lifetime than crystals formed by by dripping. After optimizing the spraying operating conditions, the optimal device based on FA0.81MA0.15Cs0.025PbI2.5Br0.45 obtained a PCE of 19.21%. Particularly, this method exhibited good reproducibility and a high fill factor due to the reduced crystal defects in the film. The champion cell obtained a fill factor as high as 80.84%, measured at AM 1.5G, 100 mW cm−2. It is expected that these findings can be beneficial for the future integrated applications of these perovskites.</p

Supple Formamidinium-Based Low-Dimension Perovskite Derivative for Sensitive and Ultrastable X-ray Detection

International audienceHalide perovskite materials possess excellent optoelec- tronic properties and have shown great potential for direct X-ray detection. Perovskite wafers are particularly attractive among various detection structures due to their scalability and ease of preparation, making them the most promising candidates for X-ray detection and array imaging applications. However, device instability and current drift caused by ionic migration are persistent challenges for perovskite detectors, especially in polycrystalline wafers with numerous grain boundaries. In this study, we examined the potential of one-dimensional (1D) δ-phase (yellow phase) formamidinium lead iodide (δ-FAPbI3) as an X-ray detection material. This material possesses a suitable band gap of 2.43 eV, which makes it highly promising for X-ray detection and imaging using compact wafers. Moreover, we found that δ-FAPbI3 has low ionic migration, low Young’s modulus, and excellent long-term stability, making it an ideal candidate for high-performance X-ray detection. Notably, the yellow phase perovskite derivative exhibits exceptional long-term atmospheric stability (RH of ≈70 ± 5%) over six months, as well as an extremely low dark current drift (3.43 × 10−4 pA cm−1 s−1 V−1), which is comparable to that of single-crystal devices. An X-ray imager with a large-size δ-FAPbI3 wafer integrated on a thin film transistor (TFT) backplane was further fabricated. Direct 2D multipixel radiographic imaging was successfully performed, demonstrating the feasibility of δ-FAPbI3 wafer detectors for sensitive and ultrastable imaging applications

Enhanced Performance and Stability of Perovskite Solar Cells Using NH₄I Interfacial Modifier

Despite organic–inorganic hybrid perovskite solar cells have rapid advances in power conversion efficiency in recent years, the serious instability of the device under practical working conditions is the current main challenge for commercialization. In this study, we have successfully inserted NH₄I as an interfacial modifier between the TiO₂ electron transport layer and perovskite layer. The result shows that it can significantly improve the quality of the perovskite films and electron extraction efficiency between the perovskite and electron transport layer. The devices with NH₄I are obtained an improved power conversion efficiency of 18.31% under AM 1.5G illumination (100 mW cm^–2). More importantly, the humidity and UV light stability of the devices are greatly improved after adding NH₄I layer. The uncoated devices only decrease by less than 15% of its original efficiency during 700-h stability tests in a humidity chamber (with a relative humidity of 80%) and the efficiency almost maintains 70% of its initial value over 20 h under UV light stress tests. This work provides a potential way by interfacial modification to significantly improve photovoltaic performance and stability of perovskite solar cells