The Photovoltaic Cell Based on CIGS: Principles and Technologies

Evaluation of design and device parameters for lead-free Sr3PBr3/Sr3NCl3 duel-layer perovskite photovoltaic device technology

The study looks into how Sr3PBr3 and Sr3NCl3 double perovskite materials can be used as absorbers in perovskite solar cells (PSCs). Computational Sr3PBr3 and Sr3NCl3 simulations were employed to assess the performance of each absorber together with electron transport layers (ETL), with a particular emphasis on optimizing ETL thickness to improve charge transport and synchronize current outputs. The simulations yielded valuable insights into the electronic and optical characteristics of the individual absorbers. Subsequently, a tandem simulation was performed to adjust each layer's thickness, ensuring that both devices' current outputs were aligned for maximum system efficiency. The findings revealed that the tandem configuration of Sr3PBr3 and Sr3NCl3 surpassed the performance of the individual absorber setups, attributed to the optimized ETL thicknesses that enhanced charge transport and facilitated effective current matching. This study makes a significant contribution to the design and optimization of tandem PSCs utilizing Sr3PBr3 and Sr3NCl3 absorbers, paving the way for improved overall device efficiency. We investigated three device configurations to find the optimum structure. FTO/SnS2/Sr3PBr3/Ni, FTO/SnS2/Sr3NCl3/Ni, and FTO/SnS2/Sr3PBr3/Sr3NCl3/Ni are considered as Device-I, II, and III. In Device-I, the execution parameters are power conversion efficiency (PCE) of 24.26%, an open-circuit voltage (V OC) of 1.23 V, a short-circuit current density (J SC) of 24.65 mA cm-2, and a fill factor (FF) of 87.42%. For Device-II, PCE, FF, V OC, and J SC are correspondingly 20.35%, 87.91%, 1.28 V, and 18.07 mA cm-2. The further refined tandem configuration achieved a PCE of 30.32%, with a V OC of 1.27 V, an FF of 90.14%, and a J SC of 26.44 mA cm-2, demonstrating the potential of this methodology in enhancing PSC performance.

Systematic inspection on the interplay between MoNa-induced sodium and the formation of MoSe2 intermediate layer in CIGSe/Mo heterostructures

The critical impact of sodium-doped molybdenum (MoNa) in shaping the MoSe2 interfacial layer, influencing the electrical properties of CIGSe/Mo heterostructures, and achieving optimal MoSe2 formation conditions, leading to improved hetero-contact quality. Notably, samples with a 600-nm-thick MoNa layer demonstrate the highest resistivity (73 μΩcm) and sheet resistance (0.45 Ω/square), highlighting the substantial impact of MoNa layer thickness on electrical conductivity. Controlled sodium diffusion through MoNa layers is essential for achieving desirable electrical characteristics, influencing Na diffusion rates, grain sizes, and overall morphology, as elucidated by EDX and FESEM analyses. Additionally, XRD results provide insights into the spontaneous peeling-off phenomenon, with the sample featuring a ~ 600-nm MoNa layer displaying the strongest diffraction peak and the largest crystal size, indicative of enhanced Mo to MoSe2 conversion facilitated by sodium presence. Raman spectra further confirm the presence of MoSe2, with its thickness correlating with MoNa layer thickness. The observed increase in resistance and decrease in conductivity with rising MoSe2 layer thickness underscore the critical importance of optimal MoSe2 formation for transitioning from Schottky to ohmic contact in CIGSe/Mo heterostructures. Ultimately, significant factors to the advancement of CIGSe thin-film solar cell production are discussed, providing nuanced insights into the interplay of MoNa and MoSe2, elucidating their collective impact on the electrical characteristics of CIGSe/Mo heterostructures.

Advancements in Photovoltaic Cell Materials: Silicon, Organic, and Perovskite Solar Cells

The evolution of photovoltaic cells is intrinsically linked to advancements in the materials from which they are fabricated. This review paper provides an in-depth analysis of the latest developments in silicon-based, organic, and perovskite solar cells, which are at the forefront of photovoltaic research. We scrutinize the unique characteristics, advantages, and limitations of each material class, emphasizing their contributions to efficiency, stability, and commercial viability. Silicon-based cells are explored for their enduring relevance and recent innovations in crystalline structures. Organic photovoltaic cells are examined for their flexibility and potential for low-cost production, while perovskites are highlighted for their remarkable efficiency gains and ease of fabrication. The paper also addresses the challenges of material stability, scalability, and environmental impact, offering a balanced perspective on the current state and future potential of these material technologies.

Proposal and Numerical Analysis of Organic/Sb2Se3 All-Thin-Film Tandem Solar Cell

The low bandgap antimony selenide (Sb₂Se₃) and wide bandgap organic solar cell (OSC) can be considered suitable bottom and top subcells for use in tandem solar cells. Some properties of these complementary candidates are their non-toxicity and cost-affordability. In this current simulation study, a two-terminal organic/Sb₂Se₃ thin-film tandem is proposed and designed through TCAD device simulations. To validate the device simulator platform, two solar cells were selected for tandem design, and their experimental data were chosen for calibrating the models and parameters utilized in the simulations. The initial OSC has an active blend layer, whose optical bandgap is 1.72 eV, while the initial Sb₂Se₃ cell has a bandgap energy of 1.23 eV. The structures of the initial standalone top and bottom cells are ITO/PEDOT:PSS/DR3TSBDT:PC₇₁BM/PFN/Al, and FTO/CdS/Sb₂Se₃/Spiro-OMeTAD/Au, while the recorded efficiencies of these individual cells are about 9.45% and 7.89%, respectively. The selected OSC employs polymer-based carrier transport layers, specifically PEDOT:PSS, an inherently conductive polymer, as an HTL, and PFN, a semiconducting polymer, as an ETL. The simulation is performed on the connected initial cells for two cases. The first case is for inverted (p-i-n)/(p-i-n) cells and the second is for the conventional (n-i-p)/(n-i-p) configuration. Both tandems are investigated in terms of the most important layer materials and parameters. After designing the current matching condition, the tandem PCEs are boosted to 21.52% and 19.14% for the inverted and conventional tandem cells, respectively. All TCAD device simulations are made by employing the Atlas device simulator given an illumination of AM1.5G (100 mW/cm²). This present study can offer design principles and valuable suggestions for eco-friendly solar cells made entirely of thin films, which can achieve flexibility for prospective use in wearable electronics.

Proposal and Design of Flexible All-Polymer/CIGS Tandem Solar Cell

Tandem solar cells (TSCs) have attracted prodigious attention for their high efficiency, which can surmount the Shockley-Queisser limit for single-junction solar cells. Flexible TSCs are lightweight and cost-effective, and are considered a promising approach for a wide range of applications. In this paper, a numerical model, based on TCAD simulation, is presented to assess the performance of a novel two-terminal (2T) all-polymer/CIGS TSC. To confirm the model, the obtained simulation results were compared with standalone fabricated all-polymer and CIGS single solar cells. Common properties of the polymer and CIGS complementary candidates are their non-toxicity and flexibility. The initial top all-polymer solar cell had a photoactive blend layer (PM7:PIDT), the optical bandgap of which was 1.76 eV, and the initial bottom cell had a photoactive CIGS layer, with a bandgap of 1.15 eV. The simulation was then carried out on the initially connected cells, revealing a power conversion efficiency (PCE) of 16.77%. Next, some optimization techniques were applied to enhance the tandem performance. Upon treating the band alignment, the PCE became 18.57%, while the optimization of polymer and CIGS thicknesses showed the best performance, reflected by a PCE of 22.73%. Moreover, it was found that the condition of current matching did not necessarily meet the maximum PCE condition, signifying the essential role of full optoelectronic simulations. All TCAD simulations were performed via an Atlas device simulator, where the light illumination was AM1.5G. The current study can offer design strategies and effective suggestions for flexible thin-film TSCs for potential applications in wearable electronics.

Environment-friendly copper-based chalcogenide thin film solar cells: status and perspectives

Copper chalcogenides (CuCh) have attracted considerable attention due to their promising potential as environmental-friendly photoactive material for lightweight and flexible thin film solar cells. Further, CuCh can be fabricated from simple to complex chemical compositions and offer a remarkable charge carrier mobility and excellent absorption coefficient with a desirable bandgap (up to ∼1.0 eV). Currently, they have demonstrated maximum power conversion efficiencies of over 23% for single-junction, around 25% and 28% for monolithic 2-Terminal (2T) and mechanically-stacked 4-Terminal (4T) perovskite/CuCh tandem solar cells, respectively. This article presents an overview of CuCh-based materials, from binary- to quaternary-CuCh compounds for single- and multi-junction solar cells. Then, we discuss the development of fabrication methods and the approaches taken to improve the performance of CuCh-based thin film itself, including chemical doping, the development of complement layers, and their potential application in flexible and lightweight devices. Finally, these technologies' stability, scalability, and toxicity aspects are discussed to enhance their current marketability.

Photovoltaic Cell Generations and Current Research Directions for Their Development

The purpose of this paper is to discuss the different generations of photovoltaic cells and current research directions focusing on their development and manufacturing technologies. The introduction describes the importance of photovoltaics in the context of environmental protection, as well as the elimination of fossil sources. It then focuses on presenting the known generations of photovoltaic cells to date, mainly in terms of the achievable solar-to-electric conversion efficiencies, as well as the technology for their manufacture. In particular, the third generation of photovoltaic cells and recent trends in its field, including multi-junction cells and cells with intermediate energy levels in the forbidden band of silicon, are discussed. We also present the latest developments in photovoltaic cell manufacturing technology, using the fourth-generation graphene-based photovoltaic cells as an example. An extensive review of the world literature led us to the conclusion that, despite the appearance of newer types of photovoltaic cells, silicon cells still have the largest market share, and research into ways to improve their efficiency is still relevant.