<span class="text_page_counter">Trang 1</span><div class="page_container" data-page="1">

The Most Influential Scientific and TechnologicalAchievement Proposal Award

<b>ENGLISH FOR SCIENCE AND TECHNOLOGYFINAL PROJECT – CASE STUDY</b>

<b>Perovskite Solar Cells - a promising technology for next-generationphotovoltaic devices</b>

Hanoi, 2023

Bui Thi Huyen - 22040536

Nguyen Thi Minh Ngoc - 22040525

</div><span class="text_page_counter">Trang 2</span><div class="page_container" data-page="2">

<b>TABLE OF CONTENTS</b>

<b>I. Executive Summary... 3</b>

<b>II. Technical description... 3</b>

<b>III. Evaluation Report... 5</b>

Innovation in design, concept and technological application... 5

Suitability for use...8

Advantages... 9

Contributions... 10

<b>References...12</b>

</div><span class="text_page_counter">Trang 3</span><div class="page_container" data-page="3">

<b>I. Executive Summary</b>

Perovskite solar cell (PSC) is a class of solar cells based on mixed organic–inorganic halideperovskites. The very first efficient solid-state perovskite cells were reported in 2012 and hadrapid progress in the following years. The confirmed efficiency of PSC had a continuousincrease and is still far from fully optimized, bringing a tantalizing prospect of higher energyconversion efficiencies and significantly lower processing costs. PSC has numerousadvantages, such as ease of production, strong solar absorption, low non-radiative carrierrecombination rates, and reasonably high carrier mobility; however, there are somedrawbacks, including toxic issues from lead or quite rapid degradation (Green, M. et al.,2014). This report will provide some background information about PSC’s technicaldescription and also the reasons for nominating it. By presenting a compelling case for thesignificant contributions of PSCs to the field of renewable energy, this nomination seeks tohonor their influence and potential as a transformative force in the scientific andtechnological landscape.

<b>II. Technical description</b>

● Category of the entry:Renewable energy technologies,solar technology advances

● General name of the entry: Perovskite solar cell (PSC)● Designer information:

According to BCC Research Report "Perovskite Solar Cells: Materials, Manufacturing andGlobal Markets" by Margareth Gagliardi, the inception of perovskite solar cells can be tracedback to the year 1839, when an esteemed German scientist named Gustav Rose whiletraveling to Russia, fortuitously stumbled upon a novel calcium titanate-based mineral in theUral Mountains (Gagliardi, M., 2018). The first incorporation of perovskite materials into asolar cell was reported in 2009 by Tsutomu Miyasaka from Toin University of Yokohama,Japan, in the Journal of the American Chemical Society. That solar cell had a powerconversion efficiency of only 3.8 percent. In 2012, Mike Lee and Henry Snaith from theUniversity of Oxford made a breakthrough discovery that perovskites can remain stable whenin contact with holes in solids. This led to the development of thin-film perovskite solar cellswithout the need for a mesoporous scaffold, which has achieved impressive efficiencies ofover 10%. This trend has continued, with new records for single-junction perovskite solar cell

</div><span class="text_page_counter">Trang 4</span><div class="page_container" data-page="4">

efficiency being set every year since 2015. Furthermore, since at least 2016, perovskitesilicon tandem solar cell records have consistently surpassed those of single-junction solarcells. In 2018, researchers from Oxford Solar Power and Berlin-Helmholtz-Zentrum havealternately broken this record. It is predicted that in 2022, the latter will achieve a recordefficiency of 32.5%.

● Technical description:

Perovskite solar cells are a type of thin-film solar cell that utilizes a perovskite-structurecompound as the light-absorbing layer. In this context, perovskite or perovskite structurerefers to the general chemical structure adapted from a mineral called perovskite. Thestructure of a perovskite solar cell can be described as basically three layers, similar to otherthird-generation photovoltaic cells (including new concepts of batteries such as concentratorbatteries, quantum dot batteries, and dye-sensitized batteries) (Tycoon Energy, 2022). Threelayers include the perovskite absorbing layer sandwiched in between two electrode layers.However, in reality, there are more than just three layers in a perovskite solar cell to improveeffectiveness. Another layer might be set between the perovskite and electrodes as well,aiming to draw out specific charges.

<i>Figure 1: The typical arrangement of a perovskite solar cell includes a transparentconductive oxide (TCO), an electron transport layer (ETL), the light-absorbing perovskitematerial, a hole transporting layer (HTL), and a metal electrode (Source: ResearchGate).</i>

Perovskite solar panels use sunlight to convert to electricity. When sunlight strikes the panel,the photons in the light are absorbed by the perovskite absorbing layer. This absorption

</div><span class="text_page_counter">Trang 5</span><div class="page_container" data-page="5">

causes electrons to be released from their atoms, leaving behind "holes" in the surface (whichare the missing electrons). The free electrons and holes, referred to as electron-hole pairs, getseparated by an electric field within the perovskite substance. This separation drives theelectrons to flow towards one electrode, while the holes flow towards the other electrode. Asa result, an electric current is generated from this flow, which then can be used to powerdevices. The electrodes are connected to an external circuit, which allows the current to flowout of the panel and be used to power devices. The circuit also ensures that the electrons andholes recombine at the electrodes, preventing the loss of energy.

<i>Figure 2: A simplified diagram of how perovskite solar cells work (Source: SolarReviews).</i>

<b>III. Evaluation Report</b>

<b>Innovation in design, concept and technological application</b>

What first makes perovskite solar cells stand out as the most influential advancement at themoment is their groundbreaking innovations in design, concept and technological application.Firstly, perovskite solar panels’ success partially results from its distinctive design structurecompared to conventional counterparts, especially the popular silicon-based ones. PSCsemploy a class of materials characterized by a perovskite crystal lattice arrangement,typically composed of mixed organic-inorganic halide perovskites in an ABX3 structure.

</div><span class="text_page_counter">Trang 6</span><div class="page_container" data-page="6">

<i>Figure 3: The crystalline perovskite structure (Source: ResearchGate).</i>

In an ABX3 pattern, 'A' represents an organic cation (such as methylammonium orformamidinium), 'B' indicates a metal cation (like lead or tin), and 'X' denotes a halide anion(for instance, iodide or bromide) (Ghosh et al., 2022). In contrast, silicon cells rely on acrystalline lattice made of pure silicon atoms. Because of that, when making perovskite solarcells, their properties or materials can be tailored or adjusted to receive the highest amount ofenergy across a broader spectrum, which is hugely limited in silicon's rigid lattice structure(Williams, 2023). And as a result, this flexibility and tunability of perovskite solar cells pavesthe way for its enhanced light absorption capabilities and overall efficiency.

Secondly, perovskite solar cells are actualizing the concept of improving efficiency whilelowering manufacturing costs. As the efficiency of these cells is of considerable significance,more energy will be absorbed in every cell, enabling the production of thinner cell films, andconsequently reducing material cost. It is recorded by Oxford PV (2020), a pioneer companyin the field of perovskite solar cells, that the power generation of 35kg of perovskite equalsthat of 7 tons of silicon, which indicates the use of materials in producing solar panels can bereduced by a hundred times. In addition, their cost-effective manufacturing using flexibletechniques like solution-based deposition further drives down production expenses.

Another noteworthy innovation of perovskite cells lies in their potential for tandem cellintegration and exploration in various applications. Tandem solar cells are made from two ormore types of solar cells with the aim of absorbing as much sunlight as possible andminimizing the spectral limitations in each type of cell. Researchers have been experimentingto integrate perovskite cells with other solar cell types and gained the very first success in a

</div><span class="text_page_counter">Trang 7</span><div class="page_container" data-page="7">

perovskite-silicon tandem cell (Cuthbertson, 2023). This perovskite-silicon tandem cellbreaks the current world record for solar cell efficiency, marking at 32.5% – higher thanperovskite and silicon cells separately. By investing in this technology, it is just in the nearfuture to achieve a higher overall efficiency of solar technology. What is more, the potentialintegration into unconventional surfaces and settings is another notable application of solarcells from perovskite. The flexibility in the fabrication of perovskite cells enables the creationof thin, lightweight, and even bendable films. As a result, the thin-film nature of theseperovskite cells opens doors for diverse applications, from integrating solar technology intobuilding materials like windows to developing portable and flexible electronic devices suchas wearable electronics or transparent coatings for structures. This adaptability marks adeparture from the rigid structures of traditional solar cells, ushering in a new era of versatilesolar technology.

<i>Figure 4: Perovskite photovoltaic glass was established in a model house in FujisawaSustainable Smart Town (Source: Panasonic Group).</i>

With all these innovative and creative aspects, perovskite batteries are considered to be agood candidate for an alternative solution, overcoming the limitations of silicon batteries -this is also what all technological developments aim for (Mr. Ted Sargent - Teacher Professorat the Department of Chemistry and Electrical and Computer Engineering at NorthwesternUniversity (USA))

</div><span class="text_page_counter">Trang 8</span><div class="page_container" data-page="8">

<b>Suitability for use</b>

Perovskite solar cells have sparked considerable interest due to their potential to revolutionizethe solar industry especially when it comes to their suitability for use. The first developmentpotential is its highly efficient power generation. It was reported in 2009 by TsutomuMiyasaka and colleagues that perovskite-based solar cells had a power conversion efficiency(PCE) of 3.8%. According to National Renewable Energy Laboratory (2022), perovskite cellsexhibit remarkable efficiency gains at above 26.1%, and it is expected that this figure willincrease to over 30% in the near future.

<i>Figure 5: The efficiency records for perovskite PV cells, compared to other PV technologies,show a current best of 25.7% for single-junction perovskite cells, as of January 26, 2022</i>

<i>(Source: National Renewable Energy Laboratory).</i>

</div><span class="text_page_counter">Trang 9</span><div class="page_container" data-page="9">

In addition to the potential for high energy conversion efficiency, perovskite solar cells havelower production costs than silicon-based cells due to their low energy-intensive constructionmethod, requiring low temperatures and expensive equipment, making them an appealingoption for large-scale renewable energy deployment.

Perovskite solar cells are a promising alternative to traditional silicon-based solar cells due totheir lightweight and flexible nature. This allows for easy installation on various surfacessuch as glass, plastic, or metal. They can also be seamlessly integrated into differentapplications, including curved surfaces like building facades or wearable devices, offering ahigh level of design flexibility and adaptability. Unlike traditional silicon solar cells,perovskite solar cells can be produced in a variety of colors and patterns, making them morevisually appealing and adaptable to different environments. This adds an element ofcustomization and personalization for users. Additionally, perovskite solar cells have a widerange of potential applications, including rooftop solar panels, building-integratedphotovoltaics (BIPV), wearable electronics, and flexible solar panels. Their versatility makesthem a more user-friendly option for a broader spectrum of users.

<i>Figure 6: Coloredperovskite solar cells</i>

It is undeniable that perovskite solar cells have significant advantages of performance,applicability and sustainability for users due to their advanced structures such as flexible

</div><span class="text_page_counter">Trang 10</span><div class="page_container" data-page="10">

cells, cells with a carbon electrode, semi transparent cells, tandem cells or “switchable” cells(Zuo et al., 2016). Firstly, perovskites technology can easily manufacture and decrease capitalexpenditure because they rely on abundant materials, such as methyl ammonia, lead, andiodine. Secondly, the band gap of perovskite solar cells can be modified through control ofthe composition of the perovskite material. Besides, perovskite materials can absorb widewavelengths of light, which makes them suitable for unique applications like Agrivoltaics,tandem to complement Silicon or other PV materials and to be placed in places where siliconPVs do not function well. Moreover, perovskite-based solar cells are showing an impressiverise in efficiency over the last decade and recent studies have even passed 30% whilesilicon-based solar cells are limited to around 29%, which hopefully will allow forhigh-performance and low-cost PVs. PSCs also have a lower weight than glass-based siliconPVs. Another advantage is that perovskite materials can be printed or painted over flexiblesurfaces and enable solar windows, entire rooftops and more since they aresolution-processable. Not only can perovskite materials enable transparent panels to beintegrated into buildings or devices, but they are also high return on investment.Furthermore, soluble production processes are highly efficient in terms of energy andmaterial waste. Last but not least, most perovskite panels can be recyclable, even reach 100%recyclability rate (The Advantages of Perovskite Solar Technology, 2023).

Perovskite solar cells made a major contribution to solar energy exploitation with highefficiency. Based on the huge advantages, PSCs are used in many technologies fromphotodetector, wearable power source to water photolysis (Zuo et al., 2016). Actually, there isa company named Saule Technologies which created innumerable promising PSCs’applications. Firstly, in 2016, the first real-life application of perovskite solar cells which is amobile phone charger that operates under artificial light was introduced. Secondly, asemi-transparent, A4-sized perovskite module was created in 2018 and tested internationallyin Poland and Japan. Last but not least, solar carport, a charging station for electric vehicles,is the third application of PSCs in the electromobility market (Saule Technologies, n.d.). Allof the mentioned applications have the potential for mass production and are widely used.Steve Albrecht, a perovskite researcher at the Technical University of Berlin, talked about thePSCs’ potential that the material was going to be scaled to a large volume in the near future(Peplow, 2023).

</div><span class="text_page_counter">Trang 11</span><div class="page_container" data-page="11">

<i>Figure 7: Mobile phone charger (Source: Saule Technologies).</i>

</div><span class="text_page_counter">Trang 12</span><div class="page_container" data-page="12">

<i>Figure 8: A4 - sized perovskite module (Source: Saule Technologies).</i>

<i>Figure 9: Solar Carport (Source: Saule Technologies).</i>

In a nutshell, this report includes three main content sections namely executive summary,technical description, and nomination for the nominee Perovskites Solar Cells. The materialof PSCs is outstanding in concept and design, user-friendliness, and creative use oftechnology. This achievement is promising and potential to be widely used in the efficientexploitation of solar power if they can address the stability issue.

3. Cuthbertson, A. (2023, May 19). Solar panel efficiency to increase 50% with first

<i>production of ‘miracle’ tandem cells. The Independent.</i>