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- Almora, Osbel, et al.
(författare)
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Device Performance of Emerging Photovoltaic Materials (Version 1)
- 2020
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6832 .- 1614-6840. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Emerging photovoltaics (PVs) focus on a variety of applications complementing large scale electricity generation. Organic, dye-sensitized, and some perovskite solar cells are considered in building integration, greenhouses, wearable, and indoor applications, thereby motivating research on flexible, transparent, semitransparent, and multi-junction PVs. Nevertheless, it can be very time consuming to find or develop an up-to-date overview of the state-of-the-art performance for these systems and applications. Two important resources for recording research cells efficiencies are the National Renewable Energy Laboratory chart and the efficiency tables compiled biannually by Martin Green and colleagues. Both publications provide an effective coverage over the established technologies, bridging research and industry. An alternative approach is proposed here summarizing the best reports in the diverse research subjects for emerging PVs. Best performance parameters are provided as a function of the photovoltaic bandgap energy for each technology and application, and are put into perspective using, e.g., the Shockley–Queisser limit. In all cases, the reported data correspond to published and/or properly described certified results, with enough details provided for prospective data reproduction. Additionally, the stability test energy yield is included as an analysis parameter among state-of-the-art emerging PVs.
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| 2. |
- Hawash, Zafer, et al.
(författare)
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Interfacial Modification of Perovskite Solar Cells Using an Ultrathin MAI Layer Leads to Enhanced Energy Level Alignment, Efficiencies, and Reproducibility
- 2017
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Ingår i: The Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 8:17, s. 3947-3953
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, we intentionally deposit an ultrathin layer of excess methylammonium iodide (MAI) on top of a methylammonium lead iodide (MAPI) perovskite film. Using photoelectron spectroscopy, we investigate the role of excess MAI at the interface between perovskite and spiro-MeOTAD hole-transport layer in standard structure perovskite solar cells (PSCs). We found that interfacial, favorable, energy-level tuning of the MAPI film can be achieved by controlling the amount of excess MAI on top of the MAPI film. Our XPS results reveal that MAI dissociates at low thicknesses (<16 nm) when deposited on MAPbI(3). It is not the MAI layer but the dissociated species that leads to the interfacial energy-level tuning. Optimized interface energetics were verified by solar cell device testing, leading to both an increase of 19% in average steady-state power conversion efficiency (PCE) and significantly improved reproducibility, which is represented by a much lower PCE standard deviation (from 15 +/- 2% to 17.2 +/- 0.4%).
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| 3. |
- Wang, Linqin
(författare)
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Organic Hole-Transport Materials for Perovskite Solar Cells
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Research on perovskite solar cells (PSCs) has undergone dramatic development since the first cells were reported in 2009, and the past decade has witnessed a significant breakthrough on their power conversion efficiencies (PCEs) from 3.8% to 25%. However, the large-scale industrialization of PSCs is still far from an easy task, due to the scarcity of high-performance and low-cost organic hole-transport materials (HTMs). Thus, the development of new generation HTMs is highly desired.The studies in this thesis aim at developing novel, inexpensive and easily synthesizable organic HTMs for application in efficient PSCs. A series of HTMs from small molecules to polymers, from doped to dopant-free were designed, synthesized and tested, to further improve the stability and reduce the cost.In Chapter 1 and Chapter 2, a brief introduction to PSCs, HTMs as well as the characterization methods used in this thesis are presented.In Chapter 3 and Chapter 4, the design and synthesis of a series of carbazole- based and spiro[fluorene-9,9'-xanthene] (SFX)-based HTMs is described. For these HTMs, the influence of substitution position, linking topology, pendant group and molecular size on the optical and electronic properties was systematically investigated, as well as their performance in solar cells.In Chapter 5, two small molecular HTMs based on extended SFX skeletons were introduced for the application in dopant-free PSCs. The effect of the extended conjugation core unit and molecular size on the electrochemical and optical properties, hole mobility, conductivity, molecular packing and PSC performance was studied in detail.In Chapter 6, a crosslinked SFX-based polymer was designed and synthesized as an efficient, low-cost, dopant-free HTM for conventional n-i-p type PSCs. The photoelectrochemical, optoelectronic and thermal properties of the designed polymer and the photovoltaic performance of the devices are discussed.
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