Roadmap on commercialization of metal halide perovskite photovoltaics

Perovskite solar cells (PSCs) represent one of the most promising emerging photovoltaic technologies due to their high power conversion efficiency. However, despite the huge progress made not only in terms of the efficiency achieved, but also fundamental understanding of the relevant physics of the devices and issues which affect their efficiency and stability, there are still unresolved problems and obstacles on the path toward commercialization of this promising technology. In this roadmap, we aim to provide a concise and up to date summary of outstanding issues and challenges, and the progress made toward addressing these issues. While the format of this article is not meant to be a comprehensive review of the topic, it provides a collection of the viewpoints of the experts in the field, which covers a broad range of topics related to PSC commercialization, including those relevant for manufacturing (scaling up, different types of devices), operation and stability (various factors), and environmental issues (in particular the use of lead). We hope that the article will provide a useful resource for researchers in the field and that it will facilitate discussions and move forward toward addressing the outstanding challenges in this fast-developing field

Response to “Comment on ‘Probing the Origins of Photodegradation in Organic-Inorganic Metal Halide Perovskites with Time-Resolved Mass Spectrometry’”

In a recent article, we investigated the photodegradation of various organic-inorganic metal halide perovskites using time-resolved mass spectrometry (MS). Dr. Juarez-Perez raises some concerns in his comment to our work, with an emphasis on distinguishing the difference in the results observed for methylammonium lead iodide perovskite (MAPbI3) in our study and his work. After reviewing Dr. Juarez-Perez‘s comment and exchanging ideas with him, we found that both articles complement each other well. To examine common ground and differences in the results and interpretations, we offer our response here to address some important issues he raised

Retrieval and Evaluation of Chlorophyll-a Concentration in Reservoirs with Main Water Supply Function in Beijing, China, Based on Landsat Satellite Images

Remote sensing retrieval is an important technology for studying water eutrophication. In this study, Guanting Reservoir with the main water supply function of Beijing was selected as the research object. Based on the measured data in 2016, 2017, and 2019, and Landsat-8 remote sensing images, the concentration and distribution of chlorophyll-a in the Guanting Reservoir were inversed. We analyzed the changes in chlorophyll-a concentration of the reservoir in Beijing and the reasons and effects. Although the concentration of chlorophyll-a in the Guanting Reservoir decreased gradually, it may still increase. The amount and stability of water storage, chlorophyll-a concentration of the supply water, and nitrogen and phosphorus concentration change are important factors affecting the chlorophyll-a concentration of the reservoir. We also found a strong correlation between the pixel values of adjacent reservoirs in the same image, so the chlorophyll-a estimation model can be applied to each other

On the Durability of Tin‐Containing Perovskite Solar Cells

Abstract Tin (Sn)‐containing perovskite solar cells (PSCs) have gained significant attention in the field of perovskite optoelectronics due to lower toxicity than their lead‐based counterparts and their potential for tandem applications. However, the lack of stability is a major concern that hampers their development. To achieve the long‐term stability of Sn‐containing PSCs, it is crucial to have a clear and comprehensive understanding of the degradation mechanisms of Sn‐containing perovskites and develop mitigation strategies. This review provides a compendious overview of degradation pathways observed in Sn‐containing perovskites, attributing to intrinsic factors related to the materials themselves and environmental factors such as light, heat, moisture, oxygen, and their combined effects. The impact of interface and electrode materials on the stability of Sn‐containing PSCs is also discussed. Additionally, various strategies to mitigate the instability issue of Sn‐containing PSCs are summarized. Lastly, the challenges and prospects for achieving durable Sn‐containing PSCs are presented

Emerging Photovoltaic (PV) Materials for a Low Carbon Economy

Emerging photovoltaic (PV) technologies have a potential to address the shortcomings of today’s energy market which heavily depends on the use of fossil fuels for electricity generation. We created inventories that offer insights into the environmental impacts and cost of all the materials used in emerging PV technologies, including perovskites, polymers, Cu2ZnSnS4 (CZTS), carbon nanotubes (CNT), and quantum dots. The results show that the CO2 emissions associated with the absorber layers are much less than the CO2 emissions associated with the contact and charge selective layers. The CdS (charge selective layer) and ITO (contact layer) have the highest environmental impacts compared to Al2O3, CuI, CuSCN, MoO3, NiO, poly (3-hexylthiophene-2,5-diyl (P3HT)), phenyl-C61-butyric acid methyl ester (PCBM), poly polystyrene sulfonate (PEDOT:PSS), SnO2, spiro-OMeTAD, and TiO2 (charge selective layers) and Al, Ag, Cu, FTO, Mo, ZnO:In, and ZnO/ZnO:Al (contact layers). The cost assessments show that the organic materials, such as polymer absorbers, CNT, P3HT and spiro-OMeTAD, are the most expensive materials. Inorganic materials would be more preferable to lower the cost of solar cells. All the remaining materials have a potential to be used in the commercial PV market. Finally, we analyzed the cost of PV materials based on their material intensity and CO2 emissions, and concluded that the perovskite absorber will be the most eco-efficient material that has the lowest cost and CO2 emissions

Perovskite-a Perfect Top Cell for Tandem Devices to Break the S-Q Limit

Up to now, multijunction cell design is the only successful way demonstrated to overcome the Shockley-Quiesser limit for single solar cells. Perovskite materials have been attracting ever-increasing attention owing to their large absorption coefficient, tunable bandgap, low cost, and easy fabrication process. With their rapidly increased power conversion efficiency, organic-inorganic metal halide perovskite-based solar cells have demonstrated themselves as the most promising candidates for next-generation photovoltaic applications. In fact, it is a dream come true for researchers to finally find a perfect top-cell candidate in tandem device design in commercially developed solar cells like single-crystalline silicon and CIGS cells used as the bottom component cells. Here, the recent progress of multijunction solar cells is reviewed, including perovskite/silicon, perovskite/CIGS, perovskite/perovskite, and perovskite/polymer multijunction cells. In addition, some perspectives on using these solar cells in emerging markets such as in portable devices, Internet of Things, etc., as well as an outlook for perovskite-based multijunction solar cells are discussed

Impact of Humidity and Temperature on the Stability of the Optical Properties and Structure of MAPbI3, MA0.7FA0.3PbI3 and (FAPbI3)0.95(MAPbBr3)0.05 Perovskite Thin Films

In situ real-time spectroscopic ellipsometry (RTSE) measurements have been conducted on MAPbI3, MA0.7FA0.3PbI3, and (FAPbI3)0.95(MAPbBr3)0.05 perovskite thin films when exposed to different levels of relative humidity at given temperatures over time. Analysis of RTSE measurements track changes in the complex dielectric function spectra and structure, which indicate variations in stability influenced by the underlying material, preparation method, and perovskite composition. MAPbI3 and MA0.7FA0.3PbI3 films deposited on commercial fluorine-doped tin oxide coated glass are more stable than corresponding films deposited on soda lime glass directly. (FAPbI3)0.95(MAPbBr3)0.05 films on soda lime glass showed improved stability over the other compositions regardless of the substrate, and this is attributed to the preparation method as well as the final composition

Enhanced stability for propene epoxidation with H2 and O2 over wormhole-like hierarchical TS-1 supported Au nanocatalyst

Designing highly efficient Au/Ti-containing catalysts for propene epoxidation with H2 and O2 harbors tremendous scientific and industrial importance. In this work, novel hydrophobic hierarchical TS-1 (HTS-1) with wormhole-like mesopores (ca. 45 nm) and small crystal size (100 nm) is firstly synthesized by a two-step crystallization method using CTAB as template. Gratifyingly, the Au/HTS-1 catalyst shows simultaneously high PO formation rate of 150 gpoh−1kgCat−1 without any promoter additive, PO selectivity of 90% and impressive stability of 100 h, which are much better than traditional Au/TS-1 catalyst. Furthermore, the intrinsic reason for the enhanced performance is elucidated by multi-techniques such as N2 physisorption, HRTEM, TGA, FT-IR and 29Si NMR. Interestingly, it is found that the coke in 0.10 wt% Au/HTS-1 catalyst partly reside in mesopores, alleviating the deactivation of micropore blocking. Moreover, the enhanced mass transfer ability and higher hydrophobicity of Au/HTS-1 catalyst also lead to reduced coke weight and absence of aromatic coke

In-situ observation of moisture-induced degradation of perovskite solar cells using laser-beam induced current

Song Z, Abate A, Watthage SC, et al. In-situ observation of moisture-induced degradation of perovskite solar cells using laser-beam induced current. In: 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC). Piscataway, NJ: IEEE; 2016: 1202-1206.Solar cells based on organic-inorganic metal halide perovskites have been the focus of photovoltaic research over the past few years due to high power conversion efficiencies up to 22.1% and inexpensive manufacturing costs. However, commercialization of perovskite PV technology is hindered by lack of long-term stability. To elucidate the degradation mechanisms in the state of the art perovskite solar cells, we used laser beam induced current (LBIC) mapping to spatially resolve the device degradation during aging under high humidity conditions. We confirm that perovskites are prone to decomposition in the presence of water. By varying the absorber and hole-transport materials of the devices, we are able to compare performance and identify the water ingress and degradation mechanisms. These results provide insight into the design of materials and device architectures that may improve operational stability of perovskite solar cells