Rise of a Giant: Perovskite Solar Cells and Its Economic Viability

Solar energy is plentiful. Over the last decades, a significant portion of the energy market has been acquired by solar power. There are several types of solar cells in the market chosen, dependent on the application (Nayak et al., 2019). Silicon solar panels are commonly found in solar farms, and for domestic use, or in other words, it is the market leader. However, due to the specific processing of the silicon materials and lack of practical applicability due to its rigid and opaque nature, the worldwide deployment of silicon technology is still not at an appreciable level, especially in developing countries. Based on this, alternative approaches have been widely studied, out of which the most relevant technologies to mention here are Dye Sensitized Solar Cells (DSSCs) (Kokkonen et al., 2021) and Organic Photovoltaics (OPV) (Inganäs, 2018). DSSCs and OPV are based on materials that are easily processed compared to silicon and have attractive characteristics such as color variability and transparency, so they can be applied to windows and can be integrated into building aesthetic designs. With the continuous developments in these technologies, scientists were refining them to beat the efficiency and the stability achieved by its rival silicon solar cells

Can Laminated Carbon Challenge Gold? Toward Universal, Scalable, and Low-Cost Carbon Electrodes for Perovskite Solar Cells

While perovskite solar cell (PSC) efficiencies are soaring at a laboratory scale, these are most commonly achieved with evaporated gold electrodes, which would present a significant expense in large-scale production. This can be remedied through the use of significantly cheaper carbon electrodes that, in contrast to metals, also do not migrate through the device. To this end, the present work investigates simple-to-prepare aluminum-supported carbon electrodes derived from commercially available, inexpensive materials that can be applied onto various hole-transporting materials and enable photovoltaic performances on par with those provided by gold electrodes. Successful integration of the new carbon-based electrode into flexible devices produced by a roll-to-roll printing technology by both pressing and lamination is demonstrated. However, temperature cycling durability tests reveal that the use of carbon electrodes based on commercial pastes is hindered by incompatibility of adhesive additives with the key components of the PSCs under heating. Resolving this issue, tailor-made graphite electrodes devoid of damaging additives are introduced, which improve the PSC stability under temperature cycling test protocol to the level provided by benchmark gold electrodes. The study highlights current challenges in developing laminated carbon electrodes in PSCs and proposes strategies toward the resolution thereof.This work was funded by the Australian Centre for Advanced Photovoltaics and Australian Renewable Energy Agency. A.N.S. also acknowledges the financial support from the Australian Research Council (Centre of Excellence CE140100012; Future Fellowship FT200100317). Monash Centre for Electron Microscopy (MCEM) and Melbourne Centre for Nano fabrication (MCN) are acknowledged for providing access to their facilities. The authors are grateful to Dr T. Zhang, A. Surmiak, Dr. N. Peris, Dr. D. Senevirathna, and Dr. N. Pai from Monash University for the experimental support throughout this study

Ionic Reactivity at Contacts and Aging of Methylammonium Lead Triiodide Perovskite Solar Cells

Hybrid lead halide perovskites have reached very large solar to electricity power conversion efficiencies, in some cases exceeding 20%. The most extensively used perovskite-based solar cell configuration comprises CH3NH3PbI3 (MAPbI3) in combination with electron (TiO2) and hole 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9-spiro-bifluorene (spiro-OMeTAD) selective contacts. The recognition that the solar cell performance is heavily affected by time scale of the measurement and preconditioning procedures has raised many concerns about the stability of the device and reliability for long-time operation. Mechanisms at contacts originate observable current–voltage distortions. Two types of reactivity sources have been identified here: (i) weak Ti–I–Pb bonds that facilitate interfacial accommodation of moving iodine ions. This interaction produces a highly reversible capacitive current originated at the TiO2/MAPbI3 interface, and it does not alter steady-state photovoltaic features. (ii) An irreversible redox peak only observable after positive poling at slow scan rates. It corresponds to the chemical reaction between spiro-OMeTAD+ and migrating I− which progressively reduces the hole transporting material conductivity and deteriorates solar cell performance.Funded by Ministerio de Economía y Competitividad. Grant Number: MAT2013-47192-C3-1-R and Generalitat Valenciana. Grant Numbers: Prometeo/2014/020, ACOMP/2015/105

Solution processable direct bandgap copper-silver-bismuth iodide photovoltaics : compositional control of dimensionality and optoelectronic properties

Altres ajuts: SRR acknowledges the support from "laCaixa" Foundation (ID 100010434; LCF/BQ/PI20/11760024). Open access publishing facilitated by Monash University, as part of the Wiley - Monash University agreement via the Council of Australian University Librarians.The search for lead-free alternatives to lead-halide perovskite photovoltaic materials resulted in the discovery of copper(I)-silver(I)-bismuth(III) halides exhibiting promising properties for optoelectronic applications. The present work demonstrates a solution-based synthesis of uniform CuAgBiI thin films and scrutinizes the effects of x on the phase composition, dimensionality, optoelectronic properties, and photovoltaic performance. Formation of pure 3D CuAgBiI at x = 1, 2D CuAgBiI at x = 2, and a mix of the two at 1 < x < 2 is demonstrated. Despite lower structural dimensionality, CuAgBiI has broader optical absorption with a direct bandgap of 1.89 ± 0.05 eV, a valence band level at -5.25 eV, improved carrier lifetime, and higher recombination resistance as compared to CuAgBiI. These differences are mirrored in the power conversion efficiencies of the CuAgBiI and CuAgBiI solar cells under 1 sun of 1.01 ± 0.06% and 2.39 ± 0.05%, respectively. The latter value is the highest reported for this class of materials owing to the favorable film morphology provided by the hot-casting method. Future performance improvements might emerge from the optimization of the CuAgBiI layer thickness to match the carrier diffusion length of ≈40-50 nm. Nonencapsulated CuAgBiI solar cells display storage stability over 240 days

Perovskite solar cells: An integrated hybrid lifecycle assessment and review in comparison with other photovoltaic technologies

Solar cells are considered as one of the prominent sources of renewable energy suitable for large-scale adoption in a carbon-constrained world and can contribute to reduced reliance on energy imports, whilst improving the security of energy supply. A new arrival in the family of solar cells technologies is the organic-inorganic halide perovskite. The major thrust for endorsing these new solar cells pertains to their potential as an economically and environmentally viable option to traditional silicon-based technology. To verify this assertion, this paper presents a critical review of some existing photovoltaic (PV) technologies in comparison with perovskite-structured solar cells (PSCs), including material and performance parameters, production processes and manufacturing complexity, economics, key technological challenges for further developments and current research efforts. At present, there is limited environmental assessment of PSCs and consequently, a methodologically robust and environmentally expansive lifecycle supply chain assessment of two types of PSC modules A and B is also undertaken within the context of other PV technologies, to assess their potential for environmentally friendly innovation in the energy sector. Module A is based on MAPbX3 perovskite structure while module B is based on CsFAPbX3 with improved stability, reproducibility and high performance efficiency. The main outcomes, presented along with sensitivity analysis, show that PSCs offer more environmentally friendly and sustainable option, with the least energy payback period, as compared to other PV technologies. The review and analysis presented provide valuable insight and guidance in identifying pathways and windows of opportunity for future PV designs towards cleaner and sustainable energy production

Adaptation to disaster

Water is a precious commodity and considered a source of life. This life giving water appears as a common thread woven through the religion, literature and art of every culture. Architectural compositions too, are greatly enhanced by the use of water. Moreover, many of the worlds earliest civilization's originated in areas where water was readily available, such as in the Nile Delta and the Indus valley. Even in Sri Lanka, early human settlements were founded near sources of water such as the Malwatu Oya. Despite water's role as a common denominator for life, it also brings death and disaster with it when it floods, showing that too much water is as bad as too little. Flooding causes extensive damage to people and property and can be considered as the most widespread natural disaster which occurs in Sri Lanka. Flooding is common in many areas of the country and the district of Colombo also has this particular problem. However, one may be tempted to ask "Are there really floods in Colombo?" The answer is a definite "yes". One may not hear of great catastrophes related to floods within the Colombo district, but it nevertheless causes much damage to property and imposes hardships on the people when parts of the city and surrounding areas get flooded after intense rainfalls of even short duration. Therefore, it is imperative that mitigatory measures be taken in order to minimise the damaging effects of floods. In this regard, Architectural solutions for housing and building and proper planning procedures incorporating regulatory controls will ensure that people will have the opportunity of coping with and adapting to floods without incurring loss or damage

Application of Inorganic Hole Transporting Materials in Perovskite Solar Cells

Despite their rapid increase in device performances, organic-inorganic hybrid “perovskite” solar cells are costly and suffer from low stability of organic hole transporting materials (HTMs) and toxicity of lead. This thesis presents the application of inorganic HTMs as alternatives to organic HTMs, development of deposition techniques for inorganic HTMs and the role of HTMs on the performance and long-term stability of devices. Record power conversion efficiencies were achieved for planar structured inorganic HTMs based devices and their stability at different illumination and temperature conditions have been investigated. Moreover, a novel bismuth-based perovskite has been investigated as a replacement for the Pb-based perovskite

Helminthiasis in dogs of University of Peradeniya premises: a potential public health problem

A sizable population of stray dogs are wandering in the premises of the University of Peradeniya and they ramble and defecate inside the faculty buildings and student hostels. This may pose a public health risk due to wide range of zoonotic parasites strays might harbour. Here we carried out a cross-sectional, coprological survey to assess the canine helminthiasis in the Peradeniya university premises. Fresh feacal samples were collected from March to June 2018 and were analyzed using a modified Sheather’s sucrose flotation technique. Sixty dogs were sampled, of which 76.6% was infected with one or more enteric helminths with a higher prevalence in stray dogs (88.6%) than owned dogs (60.0%). Seven helminth genera were recorded: Toxocara (26.7%), Spirocerca (26.7%), Strongyloides (10.0%), Trichuris (5.0%), Dipylidium (3.3%), Capillaria (3.3%) and Ancylostoma (73.3%). All seven genera were recorded in the stray dogs while Trichuris was not recorded in the owned dogs. Ancylostoma was the most prevalent infection with the highest intensity (103.4 ±198.4 Eggs per gram: EPG). There was no difference in the prevalence of Ancylostoma infections between strays (60.0%) and owned dogs (46.7%) but the intensity of infection was higher in owned dogs (155.2 EPG); range 2 - 755 EPG) than strays (71.6 EPG; range of 1 – 546 EPG), irrespective of de-worming. It could be due to development of antihelminthic resistance as routine use likely to accelerate the development of resistance in canine helminths. Except for Capillaria, other six helminths recorded were zoonotic, with a potential of humans acquiring the infections when there is close contact with dogs. Stray dogs may act as reservoirs of these infections for owned dogs and humans and vise versa. In order to control the zoonotic infections, the stray dog population in and around faculties and residential halls, has to be controlled implementing strict rules on feeding strays inside the university premises