Volcano watch: Island fissures steaming, lake water receding View comments Komanisi went toe-to-toe with Jhack and paid the price after a crushing right hook sent him flat on his back in the second round of their fight held in East London, South Africa last September.The power-punching Cebuano, who is gunning for the vacant WBA title, boasts a record of 21 wins and 16 knockouts. His last five fights ended in KOs.Ortega, who is fighting out of Tijuana, Mexico, is no pushover with an impressive win-loss card as well, winning 26 fights against only 1 loss and a draw with 12 knockouts.ADVERTISEMENT Sports Related Videospowered by AdSparcRead Next Don’t miss out on the latest news and information. Report: Disney dropping the ‘Fox’ from movie studio names LATEST STORIES Carpio hits red carpet treatment for China Coast Guard PLAY LIST 02:14Carpio hits red carpet treatment for China Coast Guard02:56NCRPO pledges to donate P3.5 million to victims of Taal eruption00:56Heavy rain brings some relief in Australia02:37Calm moments allow Taal folks some respite03:23Negosyo sa Tagaytay City, bagsak sa pag-aalboroto ng Bulkang Taal01:13Christian Standhardinger wins PBA Best Player award ‘High crimes and misdemeanors’: Trump impeachment trial begins Trump assembles a made-for-TV impeachment defense team Filipino fighter Jhack Tepora. Photo by Mark GiongcoKUALA LUMPUR—Jhack Tepora’s first world title fight could end quickly.Tepora, the undefeated Filipino featherweight, refused to offer any predictions for his upcoming showdown against Edivaldo Ortega in the main supporting bout of the Manny Pacquiao-Lucas Matthysse “Fight of Champions,” but he believes it won’t go the distance.ADVERTISEMENT MOST READ “It won’t last 12 rounds,” said Tepora in Filipino Wednesday while working out at a makeshift gym at Le Meridien Hotel.His trainer and older brother Jing-jing hinted that the knockout could come in the middle rounds, five to seven to be specific.FEATURED STORIESSPORTSGinebra beats Meralco again to capture PBA Governors’ Cup titleSPORTSAfter winning title, time for LA Tenorio to give back to Batangas folkSPORTSTim Cone still willing to coach Gilas but admits decision won’t be ‘simple yes or no’The probability of Jhack winning by stoppage is high given his reputation as a knockout artist.Jing-Jing also said Jhack thrives against fighters like Ortega and his previous opponent Lusanda Kominisi of South Africa, who have the same come-forward style. Lights inside SMX hall flicker as Duterte rants vs Ayala, Pangilinan anew Palace OKs total deployment ban on Kuwait OFWs Nadine Lustre’s phone stolen in Brazil Putin’s, Xi’s ruler-for-life moves pose challenges to West In battle of endurance, Brownlee outlasts Onuaku In fight vs corruption, Duterte now points to Ayala, MVP companies as ‘big fish’
Explore further But in a new study published in Science Advances, Dong Shi et al. have taken a closer look at spiro-OMeTAD and found that it still has a great deal of untapped potential. For the first time, they have grown single crystals of the pure material, and in doing so, they have made the surprising discovery that spiro-OMeTAD’s single-crystal structure has a hole mobility that is three orders of magnitude greater than that of its thin-film form (which is currently used in solar cells). “This paper reports a major breakthrough for the fields of perovskite and solid-state dye-sensitized solar cells by finally clarifying the potential performance of the material and showing that improving the crystallinity of the hole transport layer is the key strategy for further breakthroughs in device engineering of these solar cells,” Osman Bakr, a professor of engineering at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia and leader of the study, told Phys.org. The findings suggest that, at least in the short term, the time-consuming process of designing and synthesizing radically new organic hole conductors as replacements to spiro-OMeTAD may not be necessary.In general, perovskite solar cells and dye-sensitized solar cells are made of three critical layers. Two of these layers—the electron-transporting layer and the light-absorbing layer—are well-understood structurally. However, the mesoscale packing structure of the hole-transporting layer, which is usually spiro-OMeTAD, has so far eluded researchers, and consequently its charge transport mechanisms have remained a mystery.In the new study, the researchers figured out a way to grow pure single crystals of spiro-OMeTAD by dissolving the spiro-OMeTAD in a carefully chosen solvent. They then placed this vial inside a larger vial containing an antisolvent, in which spiro-OMeTAD does not dissolve as well, and allowed the antisolvent vapor to slowly diffuse into the inner vial. Eventually the solution in the inner vial becomes supersaturated, so that not all of the spiro-OMeTAD can stay dissolved, causing the spiro-OMeTAD to crystallize. The researchers then performed a variety of measurements on the crystals to investigate their charge transport mechanisms and other properties.The results are much more encouraging than expected, in many ways running contrary to the conventional wisdom based on the material’s large-scale structure, which suggested that the material had reached its limits. Although the method used here to grow single crystals cannot be performed at a large scale, the researchers predict that similar methods that use an antisolvent to trigger crystallization could be used to enhance the crystallinity of the thin-layer spiro-OMeTAD, improving its hole mobility in order to make more efficient solar cells.”These astonishing findings open a new direction for the development of perovskite solar cells and dye-sensitized solar cells by showing the still untapped potential of spiro-OMeTAD,” Bakr said. “They unravel a key mystery that has confounded the photovoltaic community for the last 17 years.” (Left) The set-up used to grow single crystals of spiro-OMeTAD, based on antisolvent vapor-assisted crystallization. (Right) Single crystal structure of spiro-OMeTAD. Credit: Shi, et al. ©2016 AAAS Pinholes be gone More information: Dong Shi, et al. “Spiro-OMeTAD single crystals: Remarkably enhanced charge-carrier transport via mesoscale ordering.” Science Advances. DOI: 10.1126/sciadv.1501491AbstractWe report the crystal structure and hole-transport mechanism in spiro-OMeTAD [2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene], the dominant hole-transporting material in perovskite and solid-state dye-sensitized solar cells. Despite spiro-OMeTAD’s paramount role in such devices, its crystal structure was unknown because of highly disordered solution-processed films; the hole-transport pathways remained ill-defined and the charge carrier mobilities were low, posing a major bottleneck for advancing cell efficiencies. We devised an antisolvent crystallization strategy to grow single crystals of spiro-OMeTAD, which allowed us to experimentally elucidate its molecular packing and transport properties. Electronic structure calculations enabled us to map spiro-OMeTAD’s intermolecular charge-hopping pathways. Promisingly, single-crystal mobilities were found to exceed their thin-film counterparts by three orders of magnitude. Our findings underscore mesoscale ordering as a key strategy to achieving breakthroughs in hole-transport material engineering of solar cells. © 2016 Phys.org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Journal information: Science Advances Citation: Solar cell mystery solved, expected to greatly increase efficiency (2016, April 24) retrieved 18 August 2019 from https://phys.org/news/2016-04-solar-cell-mystery-greatly-efficiency.html (Phys.org)—For the past 17 years, spiro-OMeTAD, has been keeping a secret. Despite intense research efforts, its performance as the most commonly used hole-transporting material in perovskite and dye-sensitized solar cells has remained stagnant, creating a major bottleneck for improving solar cell efficiency. Thinking that the material has given all it has to offer, many researchers have begun investigating alternative materials to replace spiro-OMeTAD in future solar cells.