This paper studies boron contamination at the interface between the p and i layers of μc-Si：H solar cells deposited in a single-chamber PECVD system. The boron depth profile in the i layer was measured by Secondary ...This paper studies boron contamination at the interface between the p and i layers of μc-Si：H solar cells deposited in a single-chamber PECVD system. The boron depth profile in the i layer was measured by Secondary Ion Mass Spectroscopy. It is found that the mixed-phase μc-Si：H materials with 40% crystalline volume fraction is easy to be affected by the residual boron in the reactor. The experimental results showed that a 500-nm thick μc-Si：H covering layer or a 30-seconds of hydrogen plasma treatment can effectively reduce the boron contamination at the p/i interface. However, from viewpoint of cost reduction, the hydrogen plasma treatment is desirable for solar cell manufacture because the substrate is not moved during the hydrogen plasma treatment.展开更多
This paper investigates several pretreatment techniques used to reduce the phosphorus contamination between solar cells. They include hydrogen plasma pretreatment, deposition of a p-type doped layer, i-a-Si：H or μc...This paper investigates several pretreatment techniques used to reduce the phosphorus contamination between solar cells. They include hydrogen plasma pretreatment, deposition of a p-type doped layer, i-a-Si：H or μc-Si：H covering layer between solar cells. Their effectiveness for the pretreatment is evaluated by means of phosphorus concentration in films, the dark conductivity of p-layer properties and cell performance.展开更多
We report on the development of single chamber deposition of microcrystalline and micromorph tandem solar cells directly onto low-cost glass substrates. The cells have pin single-junction or pin/pin double-junction st...We report on the development of single chamber deposition of microcrystalline and micromorph tandem solar cells directly onto low-cost glass substrates. The cells have pin single-junction or pin/pin double-junction structures on glass substrates coated with a transparent conductive oxide layer such as SnO2 or ZnO. By controlling boron and phosphorus contaminations, a single-junction microcrystalline silicon cell with a conversion efficiency of 7.47% is achieved with an i-layer thickness of 1.2 μm. In tandem devices, by thickness optimization of the microcrystalline silicon bottom solar cell, we obtained an initial conversion efficiency of 9.91% with an aluminum （Al） back reflector without a dielectric layer. In order to enhance the performance of the tandem solar cells, an improved light trapping structure with a ZnO/Al back reflector is used. As a result, a tandem solar cell with 11.04% of initial conversion efficiency has been obtained.展开更多
A single cathode with a cascaded bias voltage arc plasma source has been developed with a new quartz cathode chamber,instead of the previous copper chambers,to provide better diagnostic observation and access to the p...A single cathode with a cascaded bias voltage arc plasma source has been developed with a new quartz cathode chamber,instead of the previous copper chambers,to provide better diagnostic observation and access to the plasma optical emission.The cathode chamber cooling scheme is also modified to be naturally cooled only by light emission without cooling water to improve the optical thin performance in the optical path.A single-parameter physical model has been developed to describe the power dissipated in the cascaded bias voltage arc discharge argon plasmas,which have been investigated by utilizing optical emission spectroscopy（OES） and Langmuir probe.In the experiments,discharge currents from 50 A to 100 A,argon flow rates from 800 sccm to 2000 sccm and magnetic fields of 0.1 T and 0.2 T were chosen.The results show：（a） the relationship between the averaged resistivity and the averaged current density exhibits an empirical scaling law as η∝ j^（-0.63369） and the power dissipated in the arc has a strong relation with the filling factor;（b） through the quartz,the argon ions optical emission lines have been easily observed and are dominating with wavelengths between 340 nm and 520 nm,which are the emissions of Ar^＋-434.81 nm and Ar^＋-442.60 nm line,and theintensities are increasing with the arc current and decreasing with the inlet argon flow rate;and（c） the electron density and temperature can reach 2.0 × 10^19 m^-3 and 0.48 eV,respectively,under the conditions of an arc current of 90 A and a magnetic field of 0.2 T.The half-width of the ne radial profile is approximatively equal to a few Larmor radii of electrons and can be regarded as the diameter of the plasma jet in the experiments.展开更多
To investigate the effect of air-exposed biocathode（AEB） on the performance of singlechamber microbial fuel cell（SCMFC）, wastewater quality, bioelectrochemical characteristics and the electrode biofilms were resea...To investigate the effect of air-exposed biocathode（AEB） on the performance of singlechamber microbial fuel cell（SCMFC）, wastewater quality, bioelectrochemical characteristics and the electrode biofilms were researched. It was demonstrated that exposing the biocathode to air was beneficial to nitrogen removal and current generation. In Test 1 of 95%AEB, removal rates of ammonia, total nitrogen（TN） and chemical oxygen demand（COD）reached 99.34% ± 0.11%, 99.34% ± 0.10% and 90.79% ± 0.12%, respectively. The nitrogen removal loading rates were 36.38 g N/m3/day. Meanwhile, current density and power density obtained at 0.7 A/m3 and 104 m W/m3 respectively. Further experiments on opencircuit（Test 2） and carbon source（Test 3） indicated that this high performance could be attributed to simultaneous biological nitrification/denitrification and aerobic denitrification, as well as bioelectrochemical denitrification. Results of community analysis demonstrated that both microbial community structures on the surface of the cathode and in the liquid of the chamber were different. The percentage of Thauera, identified as denitrifying bacteria, maintained at a high level of over 50% in water, but decreased gradually in the AEB. Moreover, the genus Nitrosomonas, Alishewanella, Arcobacter and Rheinheimera were significantly enriched in the AEB, which might contribute to both enhancement of nitrogen removal and electricity generation.展开更多
基金Project supported by Hi-Tech Research and Development Program of China (Grant No 2007AA05Z436)Science and Technology Support Project of Tianjin (Grant No 08ZCKFGX03500)+4 种基金National Basic Research Program of China (Grant Nos 2006CB202602 and 2006CB202603)National Natural Science Foundation of China (Grant No 60506003)Starting Project of Nankai University (Grant No J02031)International Cooperation Project Between China-Greece Government (Grant No 2006DFA62390)Program for New Century Excellent Talents in University of China (NCET)
文摘This paper studies boron contamination at the interface between the p and i layers of μc-Si：H solar cells deposited in a single-chamber PECVD system. The boron depth profile in the i layer was measured by Secondary Ion Mass Spectroscopy. It is found that the mixed-phase μc-Si：H materials with 40% crystalline volume fraction is easy to be affected by the residual boron in the reactor. The experimental results showed that a 500-nm thick μc-Si：H covering layer or a 30-seconds of hydrogen plasma treatment can effectively reduce the boron contamination at the p/i interface. However, from viewpoint of cost reduction, the hydrogen plasma treatment is desirable for solar cell manufacture because the substrate is not moved during the hydrogen plasma treatment.
基金supported by Hi-Tech Research and Development Program of China (Grant Nos.2007AA05Z436 and 2009AA050602)Science and Technology Support Project of Tianjin of China (Grant No.08ZCKFGX03500)+3 种基金National Basic Research Program of China (Grant Nos.2006CB202602 and 2006CB202603)National Natural Science Foundation of China (Grant No.60976051)International Cooperation Project between China-Greece Government (Grant Nos.2006DFA62390 and 2009DFA62580)Program for New Century Excellent Talents in University of China (Grant No.NCET-08-0295)
文摘This paper investigates several pretreatment techniques used to reduce the phosphorus contamination between solar cells. They include hydrogen plasma pretreatment, deposition of a p-type doped layer, i-a-Si：H or μc-Si：H covering layer between solar cells. Their effectiveness for the pretreatment is evaluated by means of phosphorus concentration in films, the dark conductivity of p-layer properties and cell performance.
基金supported by the Hi-Tech Research and Development Program of China (Grant Nos. 2007AA05Z436 and 2009AA050602)the Science and Technology Support Project of Tianjin (Grant No. 08ZCKFGX03500)+2 种基金the National Natural Science Foundation of China (Grant No. 60976051)the International Cooperation Project between China–Greece Government (GrantNo. 2009DFA62580)the Program for New Century Excellent Talents in University of China (NCET-08-0295)
文摘We report on the development of single chamber deposition of microcrystalline and micromorph tandem solar cells directly onto low-cost glass substrates. The cells have pin single-junction or pin/pin double-junction structures on glass substrates coated with a transparent conductive oxide layer such as SnO2 or ZnO. By controlling boron and phosphorus contaminations, a single-junction microcrystalline silicon cell with a conversion efficiency of 7.47% is achieved with an i-layer thickness of 1.2 μm. In tandem devices, by thickness optimization of the microcrystalline silicon bottom solar cell, we obtained an initial conversion efficiency of 9.91% with an aluminum （Al） back reflector without a dielectric layer. In order to enhance the performance of the tandem solar cells, an improved light trapping structure with a ZnO/Al back reflector is used. As a result, a tandem solar cell with 11.04% of initial conversion efficiency has been obtained.
基金supported by the International Thermonuclear Experimental Reactor(ITER)Program Special of Ministry of Science and Technology(No.2013GB114003)National Natural Science Foundation of China(Nos.11275135,11475122)
文摘A single cathode with a cascaded bias voltage arc plasma source has been developed with a new quartz cathode chamber,instead of the previous copper chambers,to provide better diagnostic observation and access to the plasma optical emission.The cathode chamber cooling scheme is also modified to be naturally cooled only by light emission without cooling water to improve the optical thin performance in the optical path.A single-parameter physical model has been developed to describe the power dissipated in the cascaded bias voltage arc discharge argon plasmas,which have been investigated by utilizing optical emission spectroscopy（OES） and Langmuir probe.In the experiments,discharge currents from 50 A to 100 A,argon flow rates from 800 sccm to 2000 sccm and magnetic fields of 0.1 T and 0.2 T were chosen.The results show：（a） the relationship between the averaged resistivity and the averaged current density exhibits an empirical scaling law as η∝ j^（-0.63369） and the power dissipated in the arc has a strong relation with the filling factor;（b） through the quartz,the argon ions optical emission lines have been easily observed and are dominating with wavelengths between 340 nm and 520 nm,which are the emissions of Ar^＋-434.81 nm and Ar^＋-442.60 nm line,and theintensities are increasing with the arc current and decreasing with the inlet argon flow rate;and（c） the electron density and temperature can reach 2.0 × 10^19 m^-3 and 0.48 eV,respectively,under the conditions of an arc current of 90 A and a magnetic field of 0.2 T.The half-width of the ne radial profile is approximatively equal to a few Larmor radii of electrons and can be regarded as the diameter of the plasma jet in the experiments.
基金supported by the National Natural Science Foundation of China (Nos. 31270166 and 51408580)the Applied Basic Research Program of Sichuan Province (No. 2016JY0078)+1 种基金the Key Laboratory of Environmental and Applied Microbiology Chinese Academy of Sciences (No. KLCAS-2016-05)the Chengdu Science and Technology Project (No. 2015-HM0100550-SF)
文摘To investigate the effect of air-exposed biocathode（AEB） on the performance of singlechamber microbial fuel cell（SCMFC）, wastewater quality, bioelectrochemical characteristics and the electrode biofilms were researched. It was demonstrated that exposing the biocathode to air was beneficial to nitrogen removal and current generation. In Test 1 of 95%AEB, removal rates of ammonia, total nitrogen（TN） and chemical oxygen demand（COD）reached 99.34% ± 0.11%, 99.34% ± 0.10% and 90.79% ± 0.12%, respectively. The nitrogen removal loading rates were 36.38 g N/m3/day. Meanwhile, current density and power density obtained at 0.7 A/m3 and 104 m W/m3 respectively. Further experiments on opencircuit（Test 2） and carbon source（Test 3） indicated that this high performance could be attributed to simultaneous biological nitrification/denitrification and aerobic denitrification, as well as bioelectrochemical denitrification. Results of community analysis demonstrated that both microbial community structures on the surface of the cathode and in the liquid of the chamber were different. The percentage of Thauera, identified as denitrifying bacteria, maintained at a high level of over 50% in water, but decreased gradually in the AEB. Moreover, the genus Nitrosomonas, Alishewanella, Arcobacter and Rheinheimera were significantly enriched in the AEB, which might contribute to both enhancement of nitrogen removal and electricity generation.
