Light-induced or, more broadly, carrier-induced degradation (CID) in high-performance multicrystalline silicon (TIP mc-Si) solar cells remains a serious issue for many manufacturers, and the root ...cause of the degradation is still unknown. In this paper, the impact of firing temperature on the stability of lifetime test structures is investigated, and it is found that substantial CID can be triggered if peak temperatures exceed approximately 700 °C. We then investigate two pathways to stabilize the performance of industrially produced TIP mc-Si passivated emitter rear contact cells which have been fired at CID-activating temperatures (~740 °C-800 °C) currently required for silver contact formation. The first is a fast-firing approach, whereby it is demonstrated that an additional firing step at a reduced temperature after cell metallization can suppress the extent of V oc degradation by up to 80%. The second approach is the accelerated degradation and subsequent recovery of carrier lifetime through the use of high-intensity illumination during annealing at elevated temperatures. A 30 s process is found to suppress the maximum extent of degradation in V oc by up to 60% and up to 80% for longer processes. Ultimately, the results suggest that a combined approach of fast-firing and a high-intensity-illuminated anneal could achieve the best results in terms of V oc , stability.
This work presents a quantitative analysis on the relationship between the composition of PECVD silicon oxynitride and surface passivation on float zone silicon wafers with planar non-diffused ...surfaces using FTIR spectroscopy. Implied open circuit voltages of approximately 740
mV are demonstrated on both n-type and p-type substrates, with associated 1-sun effective minority carrier lifetimes of 1.8
ms and 1.1
ms respectively. Improvements in the implied open circuit voltage of up to 80
mV upon thermal annealing are presented for films with Si–H peak wavenumbers
>
2200
cm
−
1
and are attributed to increasing oxygen incorporation.
► 740
mV implied open circuit voltage achieved on n-type and p-type substrates. ► Increasing oxygen incorporation can lead to higher improvements through annealing. ► SiON provides excellent front and rear surface passivation for silicon solar cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Early recognition of symptoms of infection is essential to prevent diseases from spreading through nurseries and into planted systems. In plantations, symptoms of
Ceratocystis manginecans
infection ...are typically wilt and canker but symptoms may differ at the nursery stage and as yet have not been described for
Eucalyptus pellita
. In this study, disease symptoms were recorded over a three-month period in an
E. pellita
nursery and isolates trapped. Then, to clearly identify those relating to ceratocystis disease and any related mortality, two
C. manginecans
isolates were re-inoculated by either spraying or dipping of healthy plantlets raised by tissue culture and mini-cuttings. Many disease symptoms were observed in the nursery but only perithecia on the leaves and stems was a clear indication of the presence of a
Ceratocystis
pathogen. Nine pathogenic fungal species, including
C. manginecans
, were isolated and identified by DNA analysis. Koch’s postulates indicated that leaf blight associated with
C. manginecans
was black-brown in colour, irregular, with uneven edges and surrounded by a yellow margin or halo on the upper leaf surface. Mortality following inoculation of plantlets by spraying immediately after planting was > 70%; by contrast, mortality of mini-cuttings was < 50% if spraying was done just before transplanting but < 20% if done 7 or 14 days after transplanting. Isolate EP313C caused significantly greater mortality than isolate EP106C. The research showed that
C. manginecans
and other pathogens were present in the nursery environment and must be identified and managed as part of good nursery practice.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Efficient nanotextured black silicon solar cells passivated by an Al2O3 layer are demonstrated. The broadband antireflection of the nanotextured black silicon solar cells was provided by fabricating ...vertically aligned silicon nanowire (SiNW) arrays on the n + emitter. A highly conformal Al2O3 layer was deposited upon the SiNW arrays by the thermal atomic layer deposition (ALD) based on the multiple pulses scheme. The nanotextured black silicon wafer covered with the Al2O3 layer exhibited a low total reflectance of ∼1.5% in a broad spectrum from 400 to 800 nm. The Al2O3 passivation layer also contributes to the suppressed surface recombination, which was explored in terms of the chemical and field-effect passivation effects. An 8% increment of short-circuit current density and 10.3% enhancement of efficiency were achieved due to the ALD Al2O3 surface passivation and forming gas annealing. A high efficiency up to 18.2% was realized in the ALD Al2O3-passivated nanotextured black silicon solar cells.
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IJS, KILJ, NUK, PNG, UL, UM
The deployment of Eucalyptus pellita trees that are resistant to Ceratocystis manginecans is essential for the commercial plantations and therefore the sustainability of forest industries in ...Southeast Asia that utilize this resource. Current screening procedures are time-consuming and expensive but could be expedited with the aid of marker-assisted selection and breeding. The identification of genotypes with resistance to the disease may be facilitated if microsatellite markers developed in other Eucalyptus species are transferable and can be linked to quantitative trait loci (QTL) for disease resistance. This possibility was tested in 111 full-sib progenies and their parents by genotyping with 49 microsatellite markers developed in other Eucalyptus species. Disease development was assessed after stem inoculation with C. manginecans isolate Am60C. The disease index (DI) varied from 0 to 20% of stem length. There was a continuous distribution of resistant and susceptible seedlings with 60% in the resistant category. Of the 30 acceptable markers, 17 (56%) defined two linkage groups (LG). In each LG, one QTL with a significant logarithm of odds (LODs > 13) was identified. The transferability of microsatellite markers developed in other Eucalyptus species facilitated the rapid identification of LGs and QTLs in E. pellita. To further refine the linkage map, the testing of more microsatellite markers and a larger population of progenies are required.
Phytoplasma as a phytopathogenic prokaryote with a wide host range is a pathogen that needs more attention in Indonesia. This pathogen is relatively difficult to detect and identify due to its ...complicated biological properties. This study involved detection of phytoplasmas by polymerase chain reaction (PCR) technique with P1/P7 primers from seven symptomatic plants, i.e. Bermuda grass white leaf, bamboo yellows, witches’ broom of peanut, soybean, yard long bean, and cactus, and sweet potato little leaf. The phytoplasma DNA of the 16S rRNA gene resulting from PCR amplification was examined by digestion reaction using three endonuclease enzymes AluI, RSaI, and MSeI to generate restriction fragment length polymorphism (RFLP) profile. The seven diseased plants were confirmed positive to be associated with phytoplasma as indicated by the PCR product of 1800 bp. Based on the RFLP profiles of the three enzymes, the phytoplasmas were divided into two groups, namely group I (Bermuda grass and bamboo) and group II (peanuts, soybeans, yard long beans, cactus, and sweet potatoes). Cactus phytoplasma is a sub-group (strain) because it has a slightly different fragment of MSeI RFLP profile.
Penyakit layu bakteri yang disebabkan oleh Ralstonia solanacearum merupakan salah satu penyakit penting pada tanaman eukaliptus (Eucalyptus pellita) di Indonesia. Salah satu pendekatan teknik ...pengendalian adalah melalui pemanfaatan bakteri endofit dan fungi mikoriza arbuskula (FMA). Penelitian ini ditujukan untuk mengevaluasi keefektifan bakteri endofit dan FMA dalam menekan perkembangan penyakit layu bakteri. Terdapat sepuluh kombinasi bakteri endofit dan FMA yang di-ujikan pada bibit eukaliptus berumur satu bulan. Inokulasi R. solanacearum secara buatan dilakukan tiga bulan setelah introduksi bakteri endofit dan FMA. Percobaan dilakukan di ruang growth chamber. Peubah pengamatan meliputi periode inkubasi, insidensi penyakit, laju penyakit, agresivitas kolonisasi bakteri dengan mengamati cairan bakteri (ooze) R. solanacearum pada bibit eukaliptus, pengukuran aktivitas phenylalanine ammonia lyase (PAL), dan total fenol. Hasil penelitian menunjukkan bahwa perlakuan B5F1 (Paenibacillus polymyxa dan Glomus mosseae) memiliki kemampuan penekanan tertinggi terhadap perkembangan penyakit layu bakteri pada bibit eukaliptus, yaitu sebesar 100%. Perlakuan B5F1 menunjukkan periode inkubasi R. solanacearum lebih lama, persentase insidensi penyakit paling rendah, laju infeksi penyakit rendah, dan penghambatan agresivitas kolonisasi R. solanacearum pada eukaliptus. Sementara perlakuan B4F1 (Serratia marcescens dan G. mosseae) mampu meningkatkan aktivitas PAL dan total fenol tertinggi dibandingkan perlakuan lainnya. Berdasarkan hasil penelitian ini, perlakuan B5F1 dan B4F1 berpotensi mengendalikan penyakit layu bakteri pada tanaman eukaliptus.
Solar cells with rear localized contacts formed with and without the use of deep boron laser doping are compared as an approach to achieve a more repeatable process for high efficiency solar cells. ...In particular the paper investigates the impact of the belt firing conditions and screen printable Al paste on the quality of localized contact formation. By adjusting the firing profile, cells incorporating deep boron laser doping on the rear surface are shown to better avoid Kirkendall void formation at contact regions, while the cells without need to balance the percentage of Kirkendall void formation against the localized back surface field (LBSF) thickness. The boron laser doping can be integrated into the laser ablation process used to open the rear dielectric, which minimizes the impact on the process steps. Standard Al paste used for commercial screen printed solar cells is shown to be applicable on the boron laser doped solar cells with a peak firing temperature of 700°C. On the contrary, a special designed Al paste for LBSF applications has to be used on the cells without boron doping. An average cell efficiency of 19.8% is achieved on boron laser doped solar cells using both types of Al pastes.
•We compared localized rear contacts formed with and without boron laser doping.•We studied the impact of firing temperature and Al paste on contact formation.•Contacts formed with boron laser doping can avoid Kirkendall void formation.•Boron laser doping enabled the use of Al paste for full area BSF on LBSF cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Using hydrofluoric acid (HF) to improve the contact resistance of a screen-printed silicon solar cell with a high sheet resistance emitter was found to concurrently reduce its pseudo-fill factor. By ...treating the cell in phosphoric acid, this impact was found to be significantly reduced or eliminated. In the solar cell presented in this work, the pseudo-fill factor reduced from 82.1% to 79.9% after treating the cell in HF, but increased to 81.8% after a subsequent phosphoric acid treatment. Similar effects were found in three other screen-printed solar cells that were fired at different peak furnace temperatures and belt speeds. It was also shown that the phosphoric acid treatment alone does not affect the pseudo-fill factor of a cell. HF treatment can now be used to reduce the contact resistance of a screen-printed silicon solar cell with a high sheet resistance emitter without suffering from a lower pseudo-fill factor so that the full benefit of a HF treatment on a screen-printed silicon solar cell can be realized. This combination of HF and phosphoric acid treatments can potentially be a useful failure analysis method for screen-printed silicon solar cells in the production line and the laboratory.
•Pseudo-fill factors (pFF) were repeatedly reduced after screen-printed silicon solar cells were immersed in dilute hydrofluoric acid (HF).•A subsequent immersion in phosphoric acid (H3PO4) was able to restore the cells' pFF to its original level.•HF treatments can now be used with subsequent H3PO4 treatments so that the full benefits of HF treatments are realized.•This combined chemical treatment is potentially a useful failure analysis method for screen-printed silicon solar cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
