• 신재생에너지
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• 제4권2호
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• pp.74-80
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• 2008

To improve the blue responses of screen-printed single crystalline silicon solar cells, we investigated an emitter etch-back technique to obtain high emitter sheet resistances, where the defective dead layer on the emitter surface was etched and became thinner as the etch-back time increased, resulting in the monotonous increase of short circuit current and open circuit voltage. We found that an optimal etch-back time should be determined to achieve the maximal performance enhancement because of fill factor decrease due to a series resistance increment mainly affected by contact and lateral resistance in this case. To elucidate the reason for the fill factor decrease, we studied the resistance analysis by potential mapping to determine the contact and the lateral series resistance. As a result, we found that the fill factor decrease was attributed to the relatively fast increase of contact resistance due to the dead layer thinning down with the lowest contact resistivity when the emitter was contacted with screen-printed silver electrode.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.390-393
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• 2008

To improve the blue responses of screen-printed single crystalline silicon solar cells, we investigated an emitter etch-back technique to obtain high emitter sheet resistances, where the defective dead layer on the emitter surface was etched and became thinner as the etch-back time increased, resulting in the monotonous increase of short circuit current and open circuit voltage. We found that an optimal etch-back time should be determined to achieve the maximal performance enhancement because of fill factor decrease due to a series resistance increment mainly affected by contact and lateral resistance in this case. To elucidate the reason for the fill factor decrease, we studied the resistance analysis by potential mapping to determine the contact and the lateral series resistance. As a result, we found that the fill factor decrease was attributed to the relatively fast increase of contact resistance due to the dead layer thinning down with the lowest contact resistivity when the emitter was contacted with screen-printed silver electrode.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.355-358
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• 2009

This paper presents the technology of selective emitter for high efficiency crystalline silicon solar cell. The effect of selective emitter is analyzed by using the simulation program for solar cell, PC1D. The selective emitter shows better spectral response in short wavelength regions compared to homogeneous emitter. Therefore, the efficiency of solar cell with selective emitter can be improved by changing the sheet resistance from 60 $\Omega/\square$ to 120 $\Omega/\square$. In addition, the power loss of solar cell can be minimized by optimizing width and gap of the finger electrodes on the selective emitter.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.15-16
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• 2007

The high efficiency and low cost solar cells in order to it applied a dopant pastes diffusion process. The dopant pastes diffusion process which it uses is easily applied in screen-printing solar cells output line. in this paper, it used the Ferro 99-038 phosphorus diffusion pastes source and it analyzed a sheet resistance and a uniformity degree. And it knew the quality of the sheet resistance which it follows in temperature and time condition. The temperature variable it let and it fixed the time in 7 minutes. It will be able to measure the sheet resistance of $40({\Omega}/sq),\;30({\Omega}/sq),\; 20({\Omega}/sq)$. also average uniformity of the sheet resistance was below 5%.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1054-1056
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• 2002

High temperature Kermal diffusion from $POCl_3$ source usually used for conventional process through put of a cell manufacturing line and potentially reduce cell efficiency through bulk like time degradation. To fabricate high efficiency solar cells with minimal thermal processing, spin-on-doping(SOD) technique can be employed to emitter diffusion of a silicon solar cell. A technique is presented to emitter doping of a mono-crystalline solar cell using spin-on doping (SOD). Moreover it is shown that the sheet resistance variation with RTA temperature and time fer mono-crystalline and multi-crystalline silicon samples. This novel SOD technique was successfully used to produces 11.3% efficiency l04mm by 104mm size mono-crystalline silicon solar cells.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.56-59
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• 2011

The process conditions for high efficiency industrial crystalline Si solar cells with selective emitter were optimized. In the screen printed solar cells, the sheet resistance must be 50-60V/sq. because of metal contact resistance. But the low sheet resistance causes the increase of the recombination and blue response at the short wavelength. Therefore, the screen printed solar cells with homogeneous emitter have limitations of efficiency, and this means that the selective emitter must be used to improve cell efficiency. This work demonstrates the feasibility of a commercially available selective emitter process, based on screen printing and conventional diffusion process. Now, we improved cell efficiency from 18.29% to18.45% by transition of heavy emitter pattern and shallow emitter doping condition.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.101-104
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• 2011

Many studies in crystalline silicon solar cell fabrication have been focused on high efficiency and low cost. In this paper, we carried out the doping procedure by varying the silicon wafer thicknesses and sheet resistance. The silicon wafers with various thicknesses were obtained by shiny etching and texturing. The thicknesses of wafers were 100, 120, 150, and $180{\mu}m$. The emitter layer formed by $POCl_3$ doping process had sheet resistance with 40 and $80{\Omega}/sq$ for selective emitter application. This experiment indicated wafer thickness did not influence sheet resistance but lifetime was strongly effected.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.68-69
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• 2007

To make cost-effective solar cells, We have to use low cost material or make short process time or high temperature process. In solar cells, formation of emitter is basic and important technique according to build-up P-N junction. Diffusion process using spin-on dopants has all of this advantage. In this paper, We investigated n+ emitter formation spin-on dopants to apply crystalline silicon solar cells. We known variation of sheet resistance according to variation of temperature and single-crystalline and multi-crystalline silicon wafer using Honeywell P-8545 phosphorus spin-on dopants. We obtain uniformity of sheet resistance within 3~5% changing RPM of spin coater.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.318-321
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• 2002

This paper presents a proper condition to achieve high conversion efficiency using PC1D simulator on sri-crystalline Si solar cells. Various efficiency influencing parameters such as rear surface recombination velocity and minority carrier diffusion length in the base region, front surface recombination velocity, junction depth and doping concentration in the Emitter layer, BSF thickness and doping concentration were investigated. Optimized cell parameters were given as rear surface recombination of 1000 cm/s, minority carrier diffusion length in the base region 200 $\mu\textrm{m}$, front surface recombination velocity 100 cm/s, sheet resistivity of emitter layer 100 Ω/$\square$, BSF thickness 5 $\mu\textrm{m}$, doping concentration 5${\times}$10$\^$19/ cm$\^$-3/. Among the investigated variables, we learn that a diffusion length of base layer acts as a key factor to achieve conversion efficiency higher than 19 %.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.454-455
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• 2009

Selective emitter structure have an important research subject for crystalline silicon solar cells because it is used in production for high efficiency solar cells. A selective emitter structure with highly doped regions underneath the metal contacts is widely known to be one of the most promising high-efficiency solution in solar cell processing. Since most of the selective emitter processes require expensive extra masking and double steps process. Formation of selective emitters is not cost effective. One method that satisfies these requirements is the method of screen-printing with a phosphorus doping paste. In this paper we researched two groups of selective emitter structure process. One was using dopant paste, and the other was using solid source, in order to compare their uniformity, sheet resistance and performance condition time.