This paper identifies the contributions of p-a-SiC:H layers and i-a-Si:H layers to the open circuit voltage of p-i-n type a-Si:H solar cells deposited at a low temperature of 125℃. We find that poor quality p-a-Si...This paper identifies the contributions of p-a-SiC:H layers and i-a-Si:H layers to the open circuit voltage of p-i-n type a-Si:H solar cells deposited at a low temperature of 125℃. We find that poor quality p-a-SiC:H films under regular conditions lead to a restriction of open circuit voltage although the band gap of the i-layer varies widely. A significant improvement in open circuit voltage has been obtained by using high quality p-~SiC:H films optimized at the "low-power regime" under low silane flow rates and high hydrogen dilution conditions.展开更多
Hydrogenated silicon (Si:H) thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition (VHF PECVD) at a substrate temperature of about 170 ℃,...Hydrogenated silicon (Si:H) thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition (VHF PECVD) at a substrate temperature of about 170 ℃, The electrical, structural, and optical properties of the films were investigated. The deposited films were then applied as i-layers for p-i-n single junction solar cells. The current-voltage (I - V) characteristics of the cells were measured before and after the light soaking. The results suggest that the films deposited near the transition region have an optimum properties for application in solar cells. The cell with an i-layer prepared near the transition region shows the best stable performance.展开更多
Solar cells are now widely used as a clean method for electric energy generation. Among various type of solar cells, we compared the ability between amorphous and tandem (amorphous and polycrystalline) silicon solar c...Solar cells are now widely used as a clean method for electric energy generation. Among various type of solar cells, we compared the ability between amorphous and tandem (amorphous and polycrystalline) silicon solar cells by means of simultaneous running test. This kind of comparison is of importance practically, because the comparison of only inherent characteristics cannot include environmental parameters such as temperature totally. It was concluded that both types of solar cells provided almost the same energy for one year. The amorphous silicon solar cell provided more energy in summer while the tandem solar cell was advantageous in winter. It is due to the fact that the decrease in energy conversion at the higher cell temperature is more noticeable in tandem solar cells.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
Low energy hydrogen ion was used to passivate the electrically active defects existing in grains and grain boundaries of polycrystalline silicon solar cells.Short circuit current of H + implanted cells remarkably...Low energy hydrogen ion was used to passivate the electrically active defects existing in grains and grain boundaries of polycrystalline silicon solar cells.Short circuit current of H + implanted cells remarkably increased before and after preparing TiO 2AR(antireflective)coating.The measurements(at λ=6328) of the optical properties of H + implanted silicon samples show that:the value of absorption coefficient reached the level of a Si;refractive index n and reflectivity R significantly decreased;the optical band gap increased from 1.1 eV to 1.3 eV.The results indicate that Si H bonds have been formed after H + implantation.The calculation shows that the optical thickness cycle of TiO 2 AR coating will reduce correspondingly in order to obtain the optimum optical match between AR coating and implanted silicon since refractive index decreases after H + implantation.展开更多
Hetero-junction solar cells with an mc-Si:H window layer were achieved. The open voltage is increased while short current is decreased with increasing the mc-Si:H layer′s thickness of emitter layer. The highest of Vo...Hetero-junction solar cells with an mc-Si:H window layer were achieved. The open voltage is increased while short current is decreased with increasing the mc-Si:H layer′s thickness of emitter layer. The highest of Voc of 597 mV has obtained. When fixed the thickness of 30 nm, changing the N type from amorphous silicon layer to micro-crystalline layer, the efficiency of the hetero-junction solar cells is increased. Although the hydrogen etching before deposition enables the c-Si substrates to become rough by AFM images, it enhances the formation of epitaxial-like micro-crystalline silicon and better parameters of solar cell can be obtained by implying this process. The best result of efficiency is 13.86% with the Voc of 549.8 mV, Jsc of 32.19 mA·cm-2 and the cell′s area of 1 cm2.展开更多
Poly[decaphenylcyclopentasilane] (PDPS)-based photovoltaic cells were fabricated by using mixture solution of PDPS including boron and phosphorous elements. A doping effect of phosphorus and boron into PDPS was invest...Poly[decaphenylcyclopentasilane] (PDPS)-based photovoltaic cells were fabricated by using mixture solution of PDPS including boron and phosphorous elements. A doping effect of phosphorus and boron into PDPS was investigated on the performance of the photovoltaic devices. The solar cell provided short-circuit current density of 0.11 mA/cm2 and open-circuit voltage of 0.81 V under simulated sunlight. Microstructural analysis indicated that PDPS had an amor-phous structure, which would result in the photovoltaic properties.展开更多
Reactive sputtered boron-doped zinc oxide(BZO) film was deposited from argon,hydrogen and boron gas mixture.The reactive sputtering technique provides us the flexibility of changing the boron concentration in the prod...Reactive sputtered boron-doped zinc oxide(BZO) film was deposited from argon,hydrogen and boron gas mixture.The reactive sputtering technique provides us the flexibility of changing the boron concentration in the produced films by using the same intrinsic zinc oxide target.Textured surface was obtained in the as-deposited films.The surface morphology and the opto-electronic properties of the films can be controlled by simply varying the gas concentration ratio.By varying the gas concentration ratio,the best obtained resistivity ~6.51×10^-4Ω-cm,mobility ~19.05 cm^2 V^-1 s^-1 and sheet resistance ~7.23Ω/□ were obtained.At lower wavelength of light,the response of the deposited films improves with the increase of boron in the gas mixture and the overall transmission in the wavelength region 350-1100 nm of all the films are>85 %.We also fabricated amorphous silicon(a-Si) thin film solar cell on the best obtained BZO layers.The overall efficiency of the a-Si solar cell is 8.14 %,found on optimized BZO layer.展开更多
Interdigitated back contact-heterojunction (IBC-HJ) solar cells can have a conversion efficiency of over 25%. However, the front surface passivation and structure have a great influence on the properties of the IBC-...Interdigitated back contact-heterojunction (IBC-HJ) solar cells can have a conversion efficiency of over 25%. However, the front surface passivation and structure have a great influence on the properties of the IBC-HJ solar cell. In this paper, detailed numerical simulations have been performed to investigate the potential of front surface field (FSF) offered by stack of n-type doped and intrinsic amorphous silicon (a-Si) layers on the front surface of IBC-HJ solar cells. Simulations results clearly indicate that the electric field of FSF should be strong enough to repel minority carries and cumulate major carriers near the front surface. However, the overstrong electric field tends to drive electrons into a-Si layer, leading to severe recombination loss. The n-type doped amorphous silicon (n-a-Si) layer has been optimized in terms of doping level and thickness. The optimized intrinsic amorphous silicon (i-a-Si) layer should be as thin as possible with an energy band gap (Es) larger than 1.4 eV. In addition, the simulations concerning interface defects strongly suggest that FSF is essential when the front surface is not passivated perfectly. Without FSF, the IBC-HJ solar cells may become more sensitive to interface defect density.展开更多
Using plasma enhanced chemical vapor deposition(PECVD) at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects o...Using plasma enhanced chemical vapor deposition(PECVD) at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects of seeding processes on the growth ofμc-Si1-xGex:H i-layers and the performance ofμc-Si1-xGex:H p-i-n single junction solar cells are investigated.By applying this seeding method,theμc-Si1-xGex:H solar cell shows a significant improvement in short circuit current density(Jsc) and fill factor(FF) with an acceptable performance of blue response as aμc-Si:H solar cell even when the Ge content x increases up to 0.3.Finally,an improved efficiency of 7.05%is achieved for theμc-Si0.7Ge0.3:H solar cell.展开更多
该研究制备高电导、高透明的磷掺杂氢化纳米晶硅氧(nc-Si Ox:H)薄膜,应用于晶硅异质结(SHJ)太阳电池的窗口层以替代传统的氢化非晶硅(a-Si:H)薄膜。与以a-Si:H薄膜为窗口层的电池相比,短路电流密度提高0.5 m A/cm^(2),达到38.5 m A/cm^(...该研究制备高电导、高透明的磷掺杂氢化纳米晶硅氧(nc-Si Ox:H)薄膜,应用于晶硅异质结(SHJ)太阳电池的窗口层以替代传统的氢化非晶硅(a-Si:H)薄膜。与以a-Si:H薄膜为窗口层的电池相比,短路电流密度提高0.5 m A/cm^(2),达到38.5 m A/cm^(2),填充因子为82.7%,光电转换效率为23.5%。实验发现,在nc-Si Ox:H薄膜沉积前对本征非晶硅层表面进行处理,沉积1 nm纳米晶硅(nc-Si:H)种子层,可改善nc-Si Ox:H薄膜的晶化率,降低薄膜中的非晶相含量。与单层nc-Si Ox:H窗口层的电池相比,nc-Si:H/nc-Si Ox:H叠层结构提高电池填充因子,达到83.4%,光电转换效率增加了0.3%,达到23.8%。展开更多
Thin film solar cells have been proved the next generation photovoltaic devices due to their low cost,less material consumption and easy mass production.Among them,micro-crystalline Si and Ge based thin film solar cel...Thin film solar cells have been proved the next generation photovoltaic devices due to their low cost,less material consumption and easy mass production.Among them,micro-crystalline Si and Ge based thin film solar cells have advantages of high efficiency and ultrathin absorber layers.Yet individual junction devices are limited in photoelectric conversion efficiency because of the restricted solar spectrum range for its specific absorber.In this work,w e designed a nd simulated a multi-junction solar cell with its four sub-cells selectively absorbing the full solar spectrum including the ultraviolet,green,red as well as near infrared range,respectively.B y tuning the G e content,the record efficiency of 24.80%has been realized with the typical quadruple junction structure of a-Si:H/a-Si0.9Ge0.1:H/μc-Si:H/μc-Si0.5Ge0.5:H.To further reduce the material cost,thickness dependent device performances have been conducted.It can be found that the design of total thickness of 4μm is the optimal device design in balancing the thickness a nd the PCE.While the design of ultrathin quadruple junction device with total thickness of 2μm is the optimized device design regarding cost and long-term stability with a little bit more reduction in PCE.These results indicated that our solar cells combine the advantages of low cost and high stability.Our work may provide a general guidance rule of utilizing the full solar spectrum for developing high efficiency and ultrathin multi-junction solar cells.展开更多
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2009AA05Z422), the National Basic Research Program of China (Grant Nos. 2011CBA00705, 2011CBA00706, and 2011CBA00707), and the Natural Science Foundation of Tianjin (Grant No. 08JCZDJC22200).
文摘This paper identifies the contributions of p-a-SiC:H layers and i-a-Si:H layers to the open circuit voltage of p-i-n type a-Si:H solar cells deposited at a low temperature of 125℃. We find that poor quality p-a-SiC:H films under regular conditions lead to a restriction of open circuit voltage although the band gap of the i-layer varies widely. A significant improvement in open circuit voltage has been obtained by using high quality p-~SiC:H films optimized at the "low-power regime" under low silane flow rates and high hydrogen dilution conditions.
文摘Hydrogenated silicon (Si:H) thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition (VHF PECVD) at a substrate temperature of about 170 ℃, The electrical, structural, and optical properties of the films were investigated. The deposited films were then applied as i-layers for p-i-n single junction solar cells. The current-voltage (I - V) characteristics of the cells were measured before and after the light soaking. The results suggest that the films deposited near the transition region have an optimum properties for application in solar cells. The cell with an i-layer prepared near the transition region shows the best stable performance.
文摘Solar cells are now widely used as a clean method for electric energy generation. Among various type of solar cells, we compared the ability between amorphous and tandem (amorphous and polycrystalline) silicon solar cells by means of simultaneous running test. This kind of comparison is of importance practically, because the comparison of only inherent characteristics cannot include environmental parameters such as temperature totally. It was concluded that both types of solar cells provided almost the same energy for one year. The amorphous silicon solar cell provided more energy in summer while the tandem solar cell was advantageous in winter. It is due to the fact that the decrease in energy conversion at the higher cell temperature is more noticeable in tandem solar cells.
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.
文摘Low energy hydrogen ion was used to passivate the electrically active defects existing in grains and grain boundaries of polycrystalline silicon solar cells.Short circuit current of H + implanted cells remarkably increased before and after preparing TiO 2AR(antireflective)coating.The measurements(at λ=6328) of the optical properties of H + implanted silicon samples show that:the value of absorption coefficient reached the level of a Si;refractive index n and reflectivity R significantly decreased;the optical band gap increased from 1.1 eV to 1.3 eV.The results indicate that Si H bonds have been formed after H + implantation.The calculation shows that the optical thickness cycle of TiO 2 AR coating will reduce correspondingly in order to obtain the optimum optical match between AR coating and implanted silicon since refractive index decreases after H + implantation.
基金This project was financially supported by the National Science Foundation of Beijing, China (No.04D063)
文摘Hetero-junction solar cells with an mc-Si:H window layer were achieved. The open voltage is increased while short current is decreased with increasing the mc-Si:H layer′s thickness of emitter layer. The highest of Voc of 597 mV has obtained. When fixed the thickness of 30 nm, changing the N type from amorphous silicon layer to micro-crystalline layer, the efficiency of the hetero-junction solar cells is increased. Although the hydrogen etching before deposition enables the c-Si substrates to become rough by AFM images, it enhances the formation of epitaxial-like micro-crystalline silicon and better parameters of solar cell can be obtained by implying this process. The best result of efficiency is 13.86% with the Voc of 549.8 mV, Jsc of 32.19 mA·cm-2 and the cell′s area of 1 cm2.
文摘Poly[decaphenylcyclopentasilane] (PDPS)-based photovoltaic cells were fabricated by using mixture solution of PDPS including boron and phosphorous elements. A doping effect of phosphorus and boron into PDPS was investigated on the performance of the photovoltaic devices. The solar cell provided short-circuit current density of 0.11 mA/cm2 and open-circuit voltage of 0.81 V under simulated sunlight. Microstructural analysis indicated that PDPS had an amor-phous structure, which would result in the photovoltaic properties.
基金The work has been supported by the Science and Engineering Research Board(SERB),Department of Science and Technology(SR/FTP/PS-175/2012)。
文摘Reactive sputtered boron-doped zinc oxide(BZO) film was deposited from argon,hydrogen and boron gas mixture.The reactive sputtering technique provides us the flexibility of changing the boron concentration in the produced films by using the same intrinsic zinc oxide target.Textured surface was obtained in the as-deposited films.The surface morphology and the opto-electronic properties of the films can be controlled by simply varying the gas concentration ratio.By varying the gas concentration ratio,the best obtained resistivity ~6.51×10^-4Ω-cm,mobility ~19.05 cm^2 V^-1 s^-1 and sheet resistance ~7.23Ω/□ were obtained.At lower wavelength of light,the response of the deposited films improves with the increase of boron in the gas mixture and the overall transmission in the wavelength region 350-1100 nm of all the films are>85 %.We also fabricated amorphous silicon(a-Si) thin film solar cell on the best obtained BZO layers.The overall efficiency of the a-Si solar cell is 8.14 %,found on optimized BZO layer.
基金Acknowledgements This work is supported by the National Natural Science Foundation of China (Grant Nos. 11104319, 11274346, 51202285, 61234005, 51172268 and 51402347), the Solar Energy Action Plan of the Chinese Academy of Sciences (Grant Nos. Y1YT064001, Y1YF034001 and Y2YF014001), and Sci. & Tech. Commission Project of Beijing Municipality (Grant No. Z 151100003515003).
文摘Interdigitated back contact-heterojunction (IBC-HJ) solar cells can have a conversion efficiency of over 25%. However, the front surface passivation and structure have a great influence on the properties of the IBC-HJ solar cell. In this paper, detailed numerical simulations have been performed to investigate the potential of front surface field (FSF) offered by stack of n-type doped and intrinsic amorphous silicon (a-Si) layers on the front surface of IBC-HJ solar cells. Simulations results clearly indicate that the electric field of FSF should be strong enough to repel minority carries and cumulate major carriers near the front surface. However, the overstrong electric field tends to drive electrons into a-Si layer, leading to severe recombination loss. The n-type doped amorphous silicon (n-a-Si) layer has been optimized in terms of doping level and thickness. The optimized intrinsic amorphous silicon (i-a-Si) layer should be as thin as possible with an energy band gap (Es) larger than 1.4 eV. In addition, the simulations concerning interface defects strongly suggest that FSF is essential when the front surface is not passivated perfectly. Without FSF, the IBC-HJ solar cells may become more sensitive to interface defect density.
基金supportedbytheNationalBasicResearch Program ofChina(Nos.2011CBA00705,2011CBA00706,2011CBA00707)the Natural Science Foundation of Tianjin(No.12JCQNJC01000)the Fundamental Research Funds for the Central Universities
文摘Using plasma enhanced chemical vapor deposition(PECVD) at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects of seeding processes on the growth ofμc-Si1-xGex:H i-layers and the performance ofμc-Si1-xGex:H p-i-n single junction solar cells are investigated.By applying this seeding method,theμc-Si1-xGex:H solar cell shows a significant improvement in short circuit current density(Jsc) and fill factor(FF) with an acceptable performance of blue response as aμc-Si:H solar cell even when the Ge content x increases up to 0.3.Finally,an improved efficiency of 7.05%is achieved for theμc-Si0.7Ge0.3:H solar cell.
基金the National Natural Science Foundation of China(Grant No.51772049)the Jilin Scientific and Technological Development Program,China(Grant No.20170520159JH)+5 种基金the Thirteenth Five-Year'Scientific and Technological Research Project of the Education Department of Jilin Province,China(Grant No.JJKH20190705IG)the project of Jilin Development and Reform Commission(Grant No.2019C042)The authors also show their gratitude to the National Natural Science Foundation of China(Grant No.51802116)the Natural Science Foundation of Shandong Province(No.ZR2019BE M040)Jinbo Pang acknowledges the National Key Research and Development Program of China(Grant No.2017YFE0102700)from the Ministry of Science and Technology(MOST)of China and the Key Research and Development program of Shandong Province(Major Innovation Project of Science and Technology of Shandong Province)(No.2018YFJH0503)the University of Jinan for the Scientific Research Starting Funds.
文摘Thin film solar cells have been proved the next generation photovoltaic devices due to their low cost,less material consumption and easy mass production.Among them,micro-crystalline Si and Ge based thin film solar cells have advantages of high efficiency and ultrathin absorber layers.Yet individual junction devices are limited in photoelectric conversion efficiency because of the restricted solar spectrum range for its specific absorber.In this work,w e designed a nd simulated a multi-junction solar cell with its four sub-cells selectively absorbing the full solar spectrum including the ultraviolet,green,red as well as near infrared range,respectively.B y tuning the G e content,the record efficiency of 24.80%has been realized with the typical quadruple junction structure of a-Si:H/a-Si0.9Ge0.1:H/μc-Si:H/μc-Si0.5Ge0.5:H.To further reduce the material cost,thickness dependent device performances have been conducted.It can be found that the design of total thickness of 4μm is the optimal device design in balancing the thickness a nd the PCE.While the design of ultrathin quadruple junction device with total thickness of 2μm is the optimized device design regarding cost and long-term stability with a little bit more reduction in PCE.These results indicated that our solar cells combine the advantages of low cost and high stability.Our work may provide a general guidance rule of utilizing the full solar spectrum for developing high efficiency and ultrathin multi-junction solar cells.