Improving costs and scale reflect looming opportunities
Solar energy has the potential to play a central role in the future global energy system because of the scale of the solar resource, its ...predictability, and its ubiquitous nature. Global installed solar photovoltaic (PV) capacity exceeded 500 GW at the end of 2018, and an estimated additional 500 GW of PV capacity is projected to be installed by 2022–2023, bringing us into the era of TW-scale PV. Given the speed of change in the PV industry, both in terms of continued dramatic cost decreases and manufacturing-scale increases, the growth toward TW-scale PV has caught many observers, including many of us (
1
), by surprise. Two years ago, we focused on the challenges of achieving 3 to 10 TW of PV by 2030. Here, we envision a future with ∼10 TW of PV by 2030 and 30 to 70 TW by 2050, providing a majority of global energy. PV would be not just a key contributor to electricity generation but also a central contributor to all segments of the global energy system. We discuss ramifications and challenges for complementary technologies (e.g., energy storage, power to gas/liquid fuels/chemicals, grid integration, and multiple sector electrification) and summarize what is needed in research in PV performance, reliability, manufacturing, and recycling.
Solar cells based on copper ternary chalcogenide compounds and alloys have emerged over the last 20 years as a promising solution to the problem of high-cost solar cells. Solar power conversion ...efficiencies exceed 21% in laboratory devices using thin films of these materials, and their characteristic thinness results in negligible direct materials costs per unit area compared with wafers. Photovoltaic devices made from these materials have also been shown to be intrinsically stable, circumventing the historical disadvantage of degradation typical of earlier thin film solar cell technologies. However, these copper chalcogenide devices and materials are relatively complex. This article provides an overview of the current state of our scientific understanding and technological development of them.
The 2020 photovoltaic technologies roadmap Wilson, Gregory M; Al-Jassim, Mowafak; Metzger, Wyatt K ...
Journal of physics. D, Applied physics,
12/2020, Letnik:
53, Številka:
49
Journal Article
Recenzirano
Odprti dostop
Over the past decade, the global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven in large part by improvements in solar ...cell and module efficiencies, reduction in manufacturing costs and the realization of levelized costs of electricity that are now generally less than other energy sources and approaching similar costs with storage included. Given this success, it is a particularly fitting time to assess the state of the photovoltaics field and the technology milestones that must be achieved to maximize future impact and forward momentum. This roadmap outlines the critical areas of development in all of the major PV conversion technologies, advances needed to enable terawatt-scale PV installation, and cross-cutting topics on reliability, characterization, and applications. Each perspective provides a status update, summarizes the limiting immediate and long-term technical challenges and highlights breakthroughs that are needed to address them. In total, this roadmap is intended to guide researchers, funding agencies and industry in identifying the areas of development that will have the most impact on PV technology in the upcoming years.
The results of free-energy computational materials modeling (CMM) of the CIS ternary material system are applied to analysis of the processes of charge separation fundamental to the operation of all ...PV devices. It is known that all high-efficiency devices with CIS absorbers possess indium-rich compositions, which lie in the two-phase /spl alpha/+/spl beta/ domain of the equilibrium CIS phase diagram. The intra-absorber junction (IAJ) model presented here explores the implications of presuming that CIS absorbers are in fact two-phase mixtures and concludes that this heterogeneity is fundamental to charge separation in devices made from them. The model posits that photo-generated carrier pairs are first separated within the absorber, the holes into the /spl alpha/ and electrons into the /spl beta/-phase, respectively. These two phases segregate on a nanometer length scale to form an interpenetrating multiply-connected network which permits percolation transport of both excess carrier populations in physically distinct paths. Thus recombination of the hole and electron photocurrents within the absorber is reduced by their real-space separation.
The alternative buffer layer material Inx(OH,S)y was deposited on Cu(In,Ga)Se2 (CIGS) thin films by chemical-bath-deposition (CBD). The impurities in Inx(OH,S)y buffer layers and their atomic ...concentration were characterized by XPS and AES. In addition, AES was used to depth profile the samples. The band-gap energy of the deposited Inx(OH,S)y was determined from optical absorption data. Both the dark- and photo-I-V characteristics of the CIGS solar cells with Inx(OH,S)y buffer layers were measured, and results were compared to the CIGS cells deposited with CBD CdS buffer layers. 16 refs.
•Tumor mutation burden not always predictive of immune checkpoint inhibitor success•Intratumor heterogeneity decreases T cell response against diverse subclones•Mutagenic treatments may increase ...subclone diversity—negatively impacting therapy•Minimizing intratumor heterogeneity may increase success of immune therapy
Tumor mutation burden (TMB) is often used as a biomarker for immunogenicity and prerequisite for immune checkpoint inhibitor (ICI) therapy. However, it is becoming increasingly evident that not all tumors with high TMB respond to ICIs as expected. It has been shown that the ability of T-cells to infiltrate the tumor microenvironment and elicit a specific immune response is dependent not only on the TMB, but also on intra-tumor heterogeneity and the fraction of low-frequency subclonal mutations that make up the tumor. High intra-tumor heterogeneity leads to inefficient recognition of tumor neoantigens by T-cells due to their diluted frequency and spatial heterogeneity. Clinical studies have shown that tumors with a high degree of intra-tumor heterogeneity respond poorly to ICI therapy, and previous cytotoxic treatment may increase the intra-tumor heterogeneity and render second-line ICI therapy less effective. This paper reviews the role of ICI therapy when following chemotherapy or radiation to determine if they may be better suited as first-line therapy in patients with high TMB, low intra-tumor heterogeneity, and high PD-1, PD-L1, or CTLA-4 expression.
We perform electroluminescence (EL) intensity analysis on large-area monolithically-integrated Cu(In,Ga)Se 2 (CIGS) modules. EL was measured in two modes: a fixed voltage near V MP , and a fixed ...current injection near I MP . The EL intensity was integrated across the image to give quantitative values EL V and EL I , respectively. Differences in EL V between different modules reflect differences in average neutral bulk electronic properties (parameterized by carrier diffusion length L D ), while EL I is related to both neutral bulk and Space Charge Region (SCR) collection (dependent on both L D and non-radiative recombination lifetime parameter τ). Significant differences in EL intensity are observed between modules made with different precursor structures. By conducting large-area EL intensity analysis, we have demonstrated a method for decoupling and comparing neutral bulk and SCR collection properties of the absorbers in large-area monolithically integrated CIGS modules.
Spatially resolved electroluminescence (EL) and thermal imaging are utilized to identify scribing failures and device defects in large-area Cu(In, Ga)Se 2 modules. EL emission from modules under ...forward bias was captured by a NIR CCD camera. Thermal images under the same forward bias conditions were taken by a far IR camera. By combining measurements of EL imaging, thermal imaging, and hand-held microscopy, various EL imaging patterns have been explored and different scribing failure modes in the modules have been identified. This work demonstrates a methodology for evaluating some module performance loss mechanisms and allows quick feedback for production optimization.
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