{"title":"The stability of metallized, thin, flexible III–V structures for high temperature applications and wafer bonding","authors":"T. Bai, B. Beekley, M. Jackson, M. Goorsky","doi":"10.1109/PVSC.2015.7356355","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356355","url":null,"abstract":"The stability of thin, flexible III-V layers / solar cells with metallization was addressed. Reduced cell thickness (reduced weight) places added constraints on metallization sequences, thicknesses, and thermal budgets for these cells. We subjected a structure of a thin (few μm) III-V layers (the focus here is on InP-based structures) with metallization backing (Au, Ni, and Cu-based metallizations, several μm thick) to annealing at 200 °C, 300 °C, or 400 °C for up to a twelve hours. X-ray diffraction is a particularly useful technique as measurements from the solar cell (semiconductor) side of the stack also reveals the metallization diffraction peaks and hence any reaction byproducts. This is due to the beam penetration through the few μm thick cell layers. After 200 °C for twelve hours, x-ray diffraction and transmission electron microscopy indicate reactions between the metal layers in the stack but the semiconductor is unchanged. After 300 °C, twelve hours, there is more extensive intermetallic compound formation. However, after annealing at 400 °C, twelve hours, the III-V layer is entirely consumed. In contrast, when much thicker cells / semiconductor layers are subject to similar annealing conditions, there may not be a significant impact on performance because only a few μm of the total cell thickness is consumed. When the total thickness is only a few μm, however, the reaction between the metal contact layer and the semiconductor leads to consumption of the entire device. These results demonstrate that (i) the total cell thickness is important when considering contact-semiconductor interactions at elevated operating or processing temperatures and (ii) x-ray diffraction through the thin cell provides a detailed assessment of reactions; it can be utilized for any combination of thin film solar cell and metallization.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128289325","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}
Taizo Tanibuchi, T. Kada, N. Kasamatsu, T. Matsumura, S. Asahi, T. Kita
{"title":"Ultrafast photocarrier transport dynamics in InAs/GaAs quantum dot superlattice solar cell","authors":"Taizo Tanibuchi, T. Kada, N. Kasamatsu, T. Matsumura, S. Asahi, T. Kita","doi":"10.1109/PVSC.2015.7355965","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7355965","url":null,"abstract":"We studied time-resolved carrier transport through InAs/GaAs quantum dot superlattice (QDSL) solar cells, using time-of-flight spectroscopy with an optical probe structure lying beneath the QDSL. The density of photoexcited carriers in the top p-GaAs layer significantly influences the time-resolved photoluminescence (TRPL) of probe while TRPL of QDSL keeps unchanged. Also, the PL intensity of probe showed exponential increase as the excitation pulse energy increased, which may indicate that the dynamics of holes rule the dynamics observed in TRPL. The induced filling of QD states by strong excitation leads to the condition where carries travel over the QDSL and reach the probe faster.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128759510","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}
B. Sopori, P. Basnyat, S. Devayajanam, Rekha R. Schnepf, S. Sahoo, J. Gee, Ferdinando Severico, A. Manens, H. Seigneur, W. Schoenfeld, Steve Preece
{"title":"Analyses of diamond wire sawn wafers: Effect of various cutting parameters","authors":"B. Sopori, P. Basnyat, S. Devayajanam, Rekha R. Schnepf, S. Sahoo, J. Gee, Ferdinando Severico, A. Manens, H. Seigneur, W. Schoenfeld, Steve Preece","doi":"10.1109/PVSC.2015.7356033","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356033","url":null,"abstract":"We have evaluated surface characteristics of diamond wire cut (DWC) wafers sawn under a variety of cutting parameters. These characteristics include surface roughness, spatial frequencies of surface profiles, phase changes, damage depth, and lateral non-uniformities in the surface damage. Various cutting parameters investigated are: wire size, diamond grit size, reciprocating frequency, feed rate, and wire usage. Spatial frequency components of surface topography/roughness are influenced by individual cutting parameters as manifested by distinct peaks in the Fourier transforms of the Dektak profiles. The depth of damage is strongly controlled by diamond grit size and wire usage and to a smaller degree by the wire size.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128571772","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":"Performance restoration of dusty photovoltaic modules using electrodynamic screen","authors":"A. Sayyah, M. Horenstein, M. Mazumder","doi":"10.1109/PVSC.2015.7356134","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356134","url":null,"abstract":"Dust accumulation on optical surfaces of solar collectors is been known to cause significant losses in energy yield. The most commonly-practiced methods of cleaning solar collectors use water-based agents. This paper, however, addresses the mitigation of soiling losses on a photovoltaic cell using the electrodynamic screen (EDS) in a laboratory environment. A model for the EDS model with two stacked layers of transparent dielectric coatings is developed using finite element analysis (FEA) software, and the behavior of the electric field on the EDS surface is thoroughly examined. For the reported experiments, an EDS sample has been integrated into a PV cell for dust mitigation. Experimental results show the restoration of the short-circuit current (Isc) to more than 90% of the pre-dust value after 10 trials using standard test dust and EDS cleaning. The tests were conducted in an environmentally-controlled chamber at various applied voltages and inclination angles. In some cases, dust coagulations were observed after several cleaning cycles. To evaluate the performance of the EDS in dust-particle removal, we have studied the particle size distribution on the EDS surface after each dust deposition and cleaning cycle using a custom-built dust-deposition analyzer.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128665372","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":"Novel SiC encapsulated coaxial silicon nanowire solar cell for optimal photovoltaic performance","authors":"R. Pandey, R. Chaujar","doi":"10.1109/PVSC.2015.7355933","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7355933","url":null,"abstract":"In this paper, SiC encapsulated coaxial silicon (p-i-n) nanowire solar cell consisting of anti-reflective passivation layer (ARPL) has been designed and simulated. Photo reflectance is significantly reduced in the UV/visible spectral region due to the presence of SiC. The external quantum efficiency EQE>60% in the spectrum range of 325-625 nm wavelength and short circuit current density (Jsc), 26 mA.cm-2 as well as open circuit voltage (Voc), 291 mV has been observed. This results in 19% and 26% higher JSC and power conversion efficiency (PCE) compared to conventional SiO2 passivated coaxial nanowire silicon solar cell. Under one sun illumination (0.1 W/cm2), 4.3% PCE is achieved in SiC encapsulated coaxial silicon nanowire solar cell having the diameter and length of 300nm, 5.1μm respectively. Result indicates, SiC plays an important role in the photoelectric conversion. All the simulations have been done using calibrated software program in Silvaco atlas and devedit device simulator.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129009683","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":"Technical evaluation of the 15% of peak load PV interconnection screen","authors":"M. Reno, R. Broderick","doi":"10.1109/PVSC.2015.7356168","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356168","url":null,"abstract":"Most utilities use a standard small generator interconnection procedure (SGIP) process that includes a screen for placing potential PV interconnection requests on a fast track that do not require more detailed study. One common screening threshold is the 15% of peak load screen that fast tracks PV below a certain size. This paper performs a technical evaluation of the screen compared to a large number of simulation results for PV on 40 different feeders. Three error metrics are developed to quantify the accuracy of the screen for identifying interconnections that would cause problems or incorrectly sending a large number of allowable systems for more detailed study.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129297655","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":"Encapsulated photovoltaic blankets and modules for deployable solar arrays","authors":"Matthew Wrosch, N. Walmsley","doi":"10.1109/PVSC.2015.7356140","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356140","url":null,"abstract":"Large-area deployable solar arrays offer sizable advancements in stowed volumetric power and as-deployed specific power compared to conventional rigid solar arrays, but the traditional cell-interconnect-coverglass (CIC) scheme is no longer optimized for these embodiments. Fully encapsulated photovoltaic (PV) modules and blankets can ease the manufacture of CICs, reduce the challenges associated with electrostatic discharge (ESD) and plasma interaction, and lower the costs of assembly through semi-automated manufacture. Encapsulated PV modules have demonstrated good thermal cycle stability and module-level specific power > 400W/kg.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124552935","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":"Design and implementation of a low cost Solar Panel emulator","authors":"A. Sanaullah, H. Khan","doi":"10.1109/PVSC.2015.7356274","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356274","url":null,"abstract":"Maximum Power Point Tracking (MPPT) is an essential element of a PV system. Bench power supplies provide a reasonable approximation of solar panel behavior and can be used for initial testing. However, detailed testing with actual solar panels is required to accurately establish the performance of MPPTs. This could be a difficult and time consuming task, especially for medium and high power ratings, owing to constraining factors such as panel sizes, panel availability, testing area, daylight hours etc. An alternative to this is the use of Solar Panel Emulators (SPEs) which mimic the behavior of the panel with a reasonable accuracy. These emulators can be used to test circuits indoors for a variety of power ratings and I-V profiles while being significantly smaller in size. In this paper, we have designed and implemented a medium power SPE based on diode approximation model. By minimizing component usage, the cost of the emulator is largely reduced. The proposed circuit is simulated and then tested with loads of up to 60W with satisfactory results.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"115 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129450900","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":"Strategies for designing high efficient thin-film amorphous silicon solar cells","authors":"A. Ghahremani, A. Fathy","doi":"10.1109/PVSC.2015.7355793","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7355793","url":null,"abstract":"One method to increase light absorption inside thin-film amorphous silicon solar cells is enhancing localized fields within its depletion region. This phenomenon can occur when metallic nanoparticles (MNPs) are placed inside a structure to increase light scattering. To obtain high efficiency, however, it's crucial that most of this absorbed energy is converted to photocurrent. This paper explores the effect of embedded MNPs' size and location has for optimization purposes. Over 30% solar cell efficiency improvement can be achieved through geometry optimization; far beyond state-of-the-art for thin-film amorphous silicon solar cells.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129877969","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. Collin, J. Goffard, A. Cattoni, Clément Colin, C. Sauvan, P. Lalanne, J. Guillemoles
{"title":"Multi-resonant light trapping: New paradigm, new limits","authors":"S. Collin, J. Goffard, A. Cattoni, Clément Colin, C. Sauvan, P. Lalanne, J. Guillemoles","doi":"10.1109/PVSC.2015.7356159","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356159","url":null,"abstract":"We propose a novel approach for light trapping in solar cells. It is based on absorption through multiple resonant modes in the critical coupling regime (A=100%). A simple model is developed for the calculation of the upper limit of optical absorption in a slab of semiconductor. This multi-resonant critical coupling limit exceeds the conventional lambertian limit (4n2) for any absorber thickness. We also provide a numerical example of multi-resonant absorption in a 45nm-thick CIGS layer. It demonstrates that absorption can overcome the conventional limit on a broad spectral range.","PeriodicalId":427842,"journal":{"name":"2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129888854","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}