V. R. Whiteside, H. Esmaielpour, J. Tang, S. Vijeyaragunathan, T. Mishima, M. Santos, B. Wang, R. Yang, I. Sellers
{"title":"Evidence of suppressed hot carrier relaxation in type-II InAs/AlAs1-xSbx quantum wells","authors":"V. R. Whiteside, H. Esmaielpour, J. Tang, S. Vijeyaragunathan, T. Mishima, M. Santos, B. Wang, R. Yang, I. Sellers","doi":"10.1117/12.2237167","DOIUrl":"https://doi.org/10.1117/12.2237167","url":null,"abstract":"Hot carrier solar cells (HCSCs) have been proposed as devices, which can increase the conversion efficiency of a single junction solar cell above the Shockley-Queisser limit. For practical implementation of such systems, solar cells operating with efficient hot carrier extraction must circumvent two fundamental challenges: 1. Find an absorber material in which hot carriers are sustained either via inhibiting or circumventing phonon relaxation pathways; 2. Implement energy selective contacts in which only a narrow range of energy within the hot carrier distribution is extracted; thereby, reducing cooling losses in the contacts. Here, type-II InAs/AlAs0.16Sb0.84 quantum-wells are investigated as a candidate system for hot carrier absorbers. Continuous wave power and temperature dependent photoluminescence measurements are presented that indicate: a transition in the dominant hot carrier relaxation process from conventional phonon-mediated carrier relaxation − below 90 K − to a regime where inhibited radiative recombination dominates the hot carrier relaxation − at higher temperatures1. The reduction in the PL efficiency is strongly coupled to an increase in the hot carrier temperature extracted from the measurements. This behavior is attributed to a build-up of electrons in the QWs, which appears to inhibit electron-phonon relaxation2.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128201787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. L. Fernandes, B. Bregadiolli, A. Véron, F. Nüesch, M. A. Zaghete, Carlos Frederico de Oliveira Graeff
{"title":"Hysteresis dependence on CH3NH3PbI3 deposition method in perovskite solar cells","authors":"S. L. Fernandes, B. Bregadiolli, A. Véron, F. Nüesch, M. A. Zaghete, Carlos Frederico de Oliveira Graeff","doi":"10.1117/12.2236855","DOIUrl":"https://doi.org/10.1117/12.2236855","url":null,"abstract":"CH3NH3PbI3 perovskite solar cells are one of the most exciting technologies in the renewable energy field, resulting in over 20% power conversion efficiency. Deep understanding of the working principle is now required to turn the high efficiency solar cells into a reliable technology. In this work we have explored the role of deposition method on the crystallinity of perovskite films and its influence on the hysteresis behavior of the current-voltage characteristics. In addition Nb2O5 was used as hole blocking layer and its influence is also discussed. We have found that hysteresis is strongly dependent on both; perovskite deposition method and Nb2O5 thickness. The ideal condition where the hysteresis is suppressed or minimized was achieved by using the sequential deposition method for the perovskite semiconductor and a hole blocking layer of 50 nm.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134417381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Room temperature deposition of zinc oxide thin films by rf-magnetron sputtering for application in solar cells","authors":"Sanal K. C., R. R. Trujillo, P. K. Nair, M. Nair","doi":"10.1117/12.2238434","DOIUrl":"https://doi.org/10.1117/12.2238434","url":null,"abstract":"Recent reports indicate that thin films of oxides of zinc: ZnO, Zn(O,S), or Zn-Mg-O, could be a better buffer component than CdS to provide an adequate band alignment with orthorhombic tin sulphide in thin lm solar cells. Thin films of ZnO were grown by rf-magnetron sputtering on different substrates at room temperature. Thin films of ZnO obtained by different deposition methods show hexagonal crystal structure, usually with a preferential orientation of (002) crystallographic planes parallel to the substrate surface. However, in the present study XRD patterns indicate that thicker ZnO films on glass substrates have preferential growth of (103) planes, while that on chemically deposited CdS or ZnS films preferential orientation of (002) planes persists. Bandgap of ZnO films increases from 3.2 eV to 3.4 eV when the chamber pressure used for deposition varies from 2.3 mTorr to 6 mTorr. ZnO films were incorporated in a solar cell structure stainless steel/SnS(cubic)/SnS(orthorhombic)/SnS(cubic)/CdS/ZnO/ZnO:Al. It showed open-circuit voltage of 0.318 V, short-circuit current density of 3.6 mA/cm2 and conversion efficiency of 0.82%.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114689897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Energy storage capability of the dye sensitized solar cells via utilization of highly porous carbon electrodes","authors":"F. Rahimi, A. Takshi","doi":"10.1117/12.2237991","DOIUrl":"https://doi.org/10.1117/12.2237991","url":null,"abstract":"Dye sensitized solar cells (DSSCs) have shown promising results in the field of renewable energy owing to their low cost and portable features. In practical applications, their harvested energy could be stored in a supercapacitor once it exceeds the regular consumption. Various methods of manipulation of the active electrode have been examined to facilitate the energy storage of the system, whereas the counter electrode has always been known for its catalytic functionality and its contribution to the capacitive response of the device left a well-oriented study to be desired. In this work, the substitution of the platinum electrode with a specific porous electrode resulted in a supercapacitive behavior of the device. The photoactive electrode was fabricated using zinc oxide nanowires (ZnO) grown on a conductive transparent substrate with hydrothermal deposition method. The electrode was used to make a standard DSSC using a ruthenium dye, iodide/triiodide standard redox electrolyte, and a platinum counter electrode. The cyclic voltammetry (CV) study of the device showed a low capacitance with 350 mV open circuit voltage. Replacing the platinum counter electrode with a particularly designed porous paper-based carbon nanotube electrode resulted in a considerable difference in the CV response. A capacitive behavior was observed due to the large surface area of the counter electrode and the ZnO nanostructures on the photoactive electrode. Due to the large capacitance and relatively small photocurrent, the change in the open circuit voltage was limited. However, enhancement of the photocurrent could improve both the energy harvesting and charge storage in the device.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127774410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Crystallographic and optoelectronic properties of the novel thin film absorber Cu2GeS3","authors":"E. Robert, J. de Wild, Diego Colombara, P. Dale","doi":"10.1117/12.2236621","DOIUrl":"https://doi.org/10.1117/12.2236621","url":null,"abstract":"Thin films of Cu2GeS3 are grown by annealing copper layers in GeS and S gaseous atmosphere above 460°C. Below 500°C the cubic polymorph is formed, having inferior optoelectronic properties compared to the monoclinic phase, formed at higher temperature. The bandgap of the cubic phase lies below that of the monoclinic phase: they are determined from absorption measurements to be 1.23 and 1.55 eV respectively. Photoluminescence measurements are performed and only the monoclinic Cu2GeS3 shows a photoluminescence signal with a peak maximum at 1.57 eV. We attribute this difference between cubic and monoclinic to the higher quasi fermi level splitting of the monoclinic phase. Wavelength dependent photoelectrochemical measurements demonstrate the Cu2GeS3 to be p-type with an apparent quantum efficiency of less than 3 % above the band gap.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131393297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Interface engineering in inorganic hybrid structures towards improved photocatalysis (Conference Presentation)","authors":"Y. Xiong","doi":"10.1117/12.2237257","DOIUrl":"https://doi.org/10.1117/12.2237257","url":null,"abstract":"Designing new photocatalytic materials for improving photoconversion efficiency is a promising route to alleviate the steadily worsening environmental issues and energy crisis. Despite the invention of a large number of catalytic materials with well-defined structures, their overall efficiency in photocatalysis is still quite limited as the three key steps light harvesting, charge generation and separation, and charge transfer to surface for redox reactions have not been substantially improved. To improve each step in the complex process, there is a major trend to develop materials based on inorganic hybrid structures. In this case, interface engineering holds the promise for boosting the overall efficiency, given the key roles of interface structures in charge and energy transfer. In this talk, I will demonstrate several different approaches to designing inorganic hybrid structures with improved photocatalytic performance via interface engineering. The typical demonstrations include semiconductor-plasmonics systems for broad-spectrum light harvesting, metal-semiconductor interfaces for improved charge separation, semiconductor-MOF (metal-organic framework) configurations for activated surface reactions. It is anticipated that this series of works open a new window to rationally designing inorganic hybrid materials for photo-induced applications. References: (1) Bai, S.; Yang, L.; Wang, C.; Lin, Y.; Lu, J.; Jiang, J. and Xiong, Y.*, Angew. Chem. Int. Ed. 54, 14810-14814 (2015). (2) Bai, S.; Jiang, J.; Zhang, Q. and Xiong, Y.*, Chem. Soc. Rev. 44, 2893-2939 (2015). (3) Bai, S.; Li, X.; Kong, Q.; Long, R.; Wang, C.; Jiang, J. and Xiong, Y.*, Adv. Mater. 27, 3444-3452 (2015). (4) Bai, S.; Ge, J.; Wang, L.; Gong, M.; Deng, M.; Kong, Q.; Song, L.; Jiang, J.;* Zhang, Q.;* Luo, Y.; Xie, Y. and Xiong, Y.*, Adv. Mater. 26, 5689-5695 (2014). (5) Li, R.; Hu, J.; Deng, M.; Wang, H.; Wang, X.; Hu, Y.; Jiang, H. L.; Jiang, J.;* Zhang, Q.;* Xie, Y. and Xiong, Y.*, Adv. Mater. 26, 4783-4788 (2014).","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"9935 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130041186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Lira-Cantú, D. Tanenbaum, K. Norrman, E. Voroshazi, Martin Hermenau, M. Lloyd, Gerardo Terán-Escobar, Y. Galagan, B. Zimmermann, Markus Hösel, H. Dam, M. Jørgensen, S. Gevorgyan, L. Lutsen, D. Vanderzande, H. Hoppe, R. Rösch, U. Würfel, R. Andriessen, A. Rivaton, Gülşah Y. Uzunoğlu, David S. Germack, Birgitta Andreasen, M. Madsen, E. Bundgaard, F. Krebs
{"title":"Combined characterization techniques to understand the stability of a variety of organic photovoltaic devices: the ISOS-3 inter-laboratory collaboration","authors":"M. Lira-Cantú, D. Tanenbaum, K. Norrman, E. Voroshazi, Martin Hermenau, M. Lloyd, Gerardo Terán-Escobar, Y. Galagan, B. Zimmermann, Markus Hösel, H. Dam, M. Jørgensen, S. Gevorgyan, L. Lutsen, D. Vanderzande, H. Hoppe, R. Rösch, U. Würfel, R. Andriessen, A. Rivaton, Gülşah Y. Uzunoğlu, David S. Germack, Birgitta Andreasen, M. Madsen, E. Bundgaard, F. Krebs","doi":"10.1117/12.929579","DOIUrl":"https://doi.org/10.1117/12.929579","url":null,"abstract":"This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPVs) devices prepared by leading research laboratories. All devices have been shipped to and degraded at the Danish Technical University (DTU, formerly RISO-DTU) up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work we present a summary of the degradation response observed for the NREL sample, an inverted OPV of the type ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag/Al, under full sun stability test. The results reported from the combination of the different characterization techniques results in a proposed degradation mechanism. The final conclusion is that the failure of the photovoltaic response of the device is mainly due to the degradation of the electrodes and not to the active materials of the solar cell.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129731282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Vasyliv, O. Bilyy, Yaroslav P. Ferensovych, S. Hnatush
{"title":"Electric current generation by sulfur-reducing bacteria in microbial-anode fuel cell","authors":"O. Vasyliv, O. Bilyy, Yaroslav P. Ferensovych, S. Hnatush","doi":"10.1117/12.925211","DOIUrl":"https://doi.org/10.1117/12.925211","url":null,"abstract":"Sulfur - reducing bacteria are a part of normal microflora of natural environment. Their main function is supporting of reductive stage of sulfur cycle by hydrogen sulfide production in the process of dissimilative sulfur-reduction. At the same time these bacteria completely oxidize organic compounds with CO2 and H2O formation. It was shown that they are able to generate electric current in the two chamber microbial-anode fuel cell (MAFC) by interaction between these two processes. Microbial-anode fuel cell on the basis of sulfur- and ferric iron-reducing Desulfuromonas acetoxidans bacteria has been constructed. It has been shown that the amount of electricity generation by investigated bacteria is influenced by the concentrations of carbon source (lactate) and ferric iron chloride. The maximal obtained electric current and potential difference between electrodes equaled respectively 0.28-0.29 mA and 0.19-0.2 V per 0.3 l of bacterial suspension with 0.4 g/l of initial biomass that was grown under the influence of 0.45 mM of FeCl3 and 3 g/l of sodium lactate as primal carbon source. It has also been shown that these bacteria are resistant to different concentrations of silver ions.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132104860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Systematic reliability studies of back-contact photovoltaic modules","authors":"Victor Rosca, I. Bennett, W. Eerenstein","doi":"10.1117/12.930441","DOIUrl":"https://doi.org/10.1117/12.930441","url":null,"abstract":"Back-contact module technology offers the advantage of lower yield loss, higher power conversion efficiency, and significantly faster manufacturing as compared to conventional H-pattern modules. In this paper we present results of a systematic accelerated ageing study of ECN back-contact metallization wrap through (MWT) modules. A series of fullsize (6×10 cells) MWT modules based on combinations of four different conductive back-sheet foils, two encapsulants, and two electrically conductive adhesives were manufactured and subjected to the damp heat conditions as defined in the IEC61215 edition 2 standard. Modules that combine conductive back-sheet foil with certain types of isolation lacquer (also referred to as inner layer dielectric, ILD) and EVA showed a high failure rate. It appears that a combined effect of moisture and EVA causes a weakening of adhesion strength at Cu/ILD interface and decisively contributes to delamination at Cu/ILD interface. This delamination puts stress on the interconnection and ultimately results in interconnection failure. Removal of ILD significantly improves the stability of MWT modules in damp heat, as up to 2000 hrs of testing only up to 2.4% relative power loss was observed, and also lowers the foil cost.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129233493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Deline, A. Stokes, T. Silverman, S. Rummel, D. Jordan, S. Kurtz
{"title":"Electrical bias as an alternate method for reproducible measurement of copper indium gallium diselenide (CIGS) photovoltaic modules","authors":"C. Deline, A. Stokes, T. Silverman, S. Rummel, D. Jordan, S. Kurtz","doi":"10.1117/12.929899","DOIUrl":"https://doi.org/10.1117/12.929899","url":null,"abstract":"Light-to-dark metastable changes in thin-film photovoltaic (PV) modules can introduce uncertainty when measuring module performance on indoor flash testing equipment. This study describes a method to stabilize module performance through forward-bias current injection rather than light exposure. Measurements of five pairs of thin-film copper indium gallium diselenide (CIGS) PV modules indicate that forward-bias exposure maintained the PV modules at a stable condition (within 1%) while the unbiased modules degraded in performance by up to 12%. It was also found that modules exposed to forward bias exhibited stable performance within about 3% of their long-term outdoor exposed performance. This carrier-injection method provides a way to reduce uncertainty arising from fast transients in thin-film module performance between the time a module is removed from light exposure and when it is measured indoors, effectively simulating continuous light exposure by injecting minority carriers that behave much as photocarriers do. This investigation also provides insight into the initial light-induced transients of thin-film modules upon outdoor deployment.","PeriodicalId":140444,"journal":{"name":"Optics + Photonics for Sustainable Energy","volume":"9 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130040239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}