Perovskite (structure)

About: Perovskite (structure) is a research topic. Over the lifetime, 51482 publications have been published within this topic receiving 1541750 citations.

Potassium Incorporation for Enhanced Performance and Stability of Fully Inorganic Cesium Lead Halide Perovskite Solar Cells

Abstract: Thermally unstable nature of hybrid organic–inorganic perovskites has been a major obstacle to fabricating the long-term operational device. A cesium lead halide perovskite has been suggested as an alternative light absorber, due to its superb thermal stability. However, the phase instability and poor performance are hindering the further progress. Here, cesium lead halide perovskite solar cells with enhanced performance and stability are demonstrated via incorporating potassium cations. Based on Cs0.925K0.075PbI2Br, the planar-architecture device achieves a power conversion efficiency of 10.0%, which is a remarkable record in the field of inorganic perovskite solar cells. In addition, the device shows an extended operational lifetime against air. Our research will stimulate the development of cesium lead halide perovskite materials for next-generation photovoltaics.

Accelerated degradation of methylammonium lead iodide perovskites induced by exposure to iodine vapour

Abstract: Efficiencies of organic–inorganic lead halide perovskite solar cells (PSCs) have significantly increased in recent years, but instability issues impede their further development and application. Previous studies reported that volatile species (for example, iodine, I2) were generated when perovskites were subjected to moisture, oxygen, light illumination, applied electric field, and thermal stress (all of which are relevant to the operation of PSCs in practical applications). Here we show that I2 vapour causes severe degradation of MAPbI3 (MA: CH3NH3+) perovskite, due to chemical chain reactions. Furthermore, I2 vapour could also induce degradation of other iodide-based perovskites, such as FAPbI3 (FA: HC(NH2)2+) and FA0.8Cs0.2PbI3. The results reveal a universal degradation factor for iodide-based perovskite by I2. As the release of I2 is nearly inevitable during practical applications, this work suggests that MAPbI3 may not be suitable for long-term stable solar cells and it is imperative to develop other types of perovskite material to achieve stable PSCs. Extensive efforts are under way to tackle the degradation issue—one of the biggest challenges for the practical application of perovskite-based solar cells. Here the authors show that CH3NH3PbI3 and several other iodine-containing perovskites are inherently unstable due to decomposition caused by self-generated I2.

Rubidium Multication Perovskite with Optimized Bandgap for Perovskite-Silicon Tandem with over 26% Efficiency

Abstract: Rubidium (Rb) is explored as an alternative cation to use in a novel multication method with the formamidinium/methylammonium/cesium (Cs) system to obtain 1.73 eV bangap perovskite cells with negligible hysteresis and steady state efficiency as high as 17.4%. The study shows the beneficial effect of Rb in improving the crystallinity and suppressing defect migration in the perovskite material. The light stability of the cells examined under continuous illumination of 12 h is improved upon the addition of Cs and Rb. After several cycles of 12 h light–dark, the cell retains 90% of its initial efficiency. In parallel, sputtered transparent conducting oxide thin films are developed to be used as both rear and front transparent contacts on quartz substrate with less than 5% parasitic absorption of near infrared wavelengths. Using these developments, semi-transparent perovskite cells are fabricated with steady state efficiency of up to 16.0% and excellent average transparency of ≈84% between 720 and 1100 nm. In a tandem configuration using a 23.9% silicon cell, 26.4% efficiency (10.4% from the silicon cell) in a mechanically stacked tandem configuration is demonstrated which is very close to the current record for a single junction silicon cell of 26.6%.

Highly stable, phase pure Cs2AgBiBr6 double perovskite thin films for optoelectronic applications

Abstract: Hybrid lead halide perovskites have emerged as high-performing semiconductors for optoelectronic applications such as photovoltaics. However, their toxicity and stability issues represent significant challenges. Recently, double perovskites have been suggested as an alternative and, especially, Cs2AgBiX6 (X = Cl, Br) has proved to be a promising material as it is non-toxic and highly stable. However, the low solubility of precursors has so far hampered the fabrication of high quality films. Here, we demonstrate for the first time the fabrication of Cs2AgBiBr6 films and incorporate them into working devices. Powder X-ray diffraction measurements revealed that high annealing temperatures of at least 250 °C are required to fully convert the precursors into Cs2AgBiBr6. After the optimization of the synthesis conditions, photovoltaic devices comprising our Cs2AgBiBr6 films show power conversion efficiencies (PCE) close to 2.5% and a open circuit voltage (Voc) exceeding one volt, which is currently the highest Voc reported for a bismuth halide based perovskite, showing the potential of double perovskites as the absorber material. Furthermore, our results revealed excellent stability of the devices upon exposure to working conditions without encapsulation. Our work opens the way to a new class of perovskites with significant potential for optoelectronic applications.