• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.234-234
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• 2010

Most high efficiency silicon solar cells use a passivated selective emitter. It have been an important research subject for crystalline silicon solar cells for decades. It is being used in production for high efficiency solar cells. Most of the selective emitter process require expensive extra masking, etching steps, and a double diffusion process making selective emitters not cost effective. In this paper, we study method for single diffusion step selective emitter process as an alternative to not cost effective double diffusion process. Cost effective selective emitter that the efficiency should be increased significantly (mare than 0.2%) and that the process should simple, robust and cheap.

• Journal of the Semiconductor & Display Technology
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• v.12 no.3
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• pp.47-51
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• 2013

Current research trends of solar cells has focused on the high conversion efficiency and low-cost production technology. Passivation technology that can be easily adapted to mass production. Therefore, this study conducted experiments with aim of the following two methods for the fabrication of high-efficiency crystalline silicon solar cells. In the first task, an attempt is formation of local Al-BSF to a number of locally doped dots to increase the conversion efficiency of solar cells to reduce the loss of $V_{oc}$ overcome. The second major task, rear surface apply in $Al_2O_3/SiN_x$ stack layer, $Al_2O_3$ prominent negative fixed charge characteristics. As the result of task, Local Al-BSF and $Al_2O_3/SiN_x$ stack layer applied to the p-type single crystalline silicon solar cells, the average $V_{oc}$ of 644mV, $I_{sc}$ of 918mV and conversion efficiency of 18.70% were obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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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.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.299.2-299.2
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• 2013

We investigated the potassium remaining on a crystalline silicon solar cell after potassium hydroxide (KOH) etching and its effect on the lifetime of the solar cell. KOH etching is generally used to remove the saw damage caused by cutting a Si ingot; it can also be used to etch the rear side of a textured crystalline silicon solar cell before atomic layer-deposited Al2O3 growth. However, the potassium remaining after KOH etching is known to be detrimental to the efficiency of Si solar cells. In this study, we etched a crystalline silicon solar cell in three ways in order to determine the effect of the potassium remnant on the efficiency of Si solar cells. After KOH etching, KOH and tetramethylammonium hydroxide (TMAH) were used to etch the rear side of a crystalline silicon solar cell. To passivate the rear side, an Al2O3 layer was deposited by atomic layer deposition (ALD). After ALD Al2O3 growth on the KOH-etched Si surface, we measured the lifetime of the solar cell by quasi steady-state photoconductance (QSSPC, Sinton WCT-120) to analyze how effectively the Al2O3 layer passivated the interface of the Al2O3 layer and the Si surface. Secondary ion mass spectroscopy (SIMS) was also used to measure how much potassium remained on the surface of the Si wafer and at the interface of the Al2O3 layer and the Si surface after KOH etching and wet cleaning.

• Journal of the Korean Solar Energy Society
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• v.37 no.3
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• pp.33-45
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• 2017

Crystalline silicon photovoltaic module certification began in 2007. "Renewable Energy Equipment Certification Scheme" was implemented until July 28, 2015. Then, the scheme was changed to "KS Certification Scheme" since July 29, 2015. A total of 2,331 models have been certified by 2016. The proportion of multi crystalline modules in certified products is higher than that of mono crystalline modules, and Korean modules account for 78% of the total certification modules. Chinese solar cells account for the highest percentage of 40% of the total modules and 62.4% of modules certified in 2016 use Chinese solar cells. With the development of technology, module power is continuously increasing, and efficiency is also rising. The average efficiency of mono crystalline module is 0.74% higher than the average of multi crystalline module. As a result of comparing domestic module with Chinese module, the highest efficiency of mono crystalline module and multi crystalline module and the average efficiency of mono crystalline module are higher than those of Chinese module, but the average efficiency of multi crystalline module is similar to that of Chinese module.

• Current Photovoltaic Research
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• v.1 no.1
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• pp.11-16
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• 2013

The current solar cell industry is experiencing a temporary plateau due to a sluggish economy and oversupply. It is expected that the solar industry can see similar growth to that of the recent past by overcoming the current situation, as there is growing demand globally for solar energy. The current situation led to restructuring of the world's solar industry, and domestic firms will need to have competitiveness through strategic approaches and proprietary technology to survive in the global solar market. Crystalline and amorphous silicon based solar cells have led the solar industry and occupied half or more of the market thus far. They will do so in the future PV market as well by playing a pivotal role in the solar industry. In this paper, the current status and prospects of silicon based solar cells, from materials to comprehensive and high efficiency technology that can emerge in the future, are discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.223-224
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• 2008

Important element are low cost, high-efficiency crystalline silicon solar cells. in this paper, Will be able to contribute in low cost, high-efficiency silicon solar cells, Applies oxide/nitride passivation, produced screen-printed solar cells. and the Measures efficiency, and evaluated a justice quality oxide/nitride passivation screen-printed solar cells.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.565-569
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• 2006

Plasma enhanced chemical vapor deposition(PECVD) is a well established technique for the deposition of hydrogenated film of silicon nitride (SiNx:H), which is commonly used as an antireflection coating as well as passivating layer in crystalline silicon solar cell. PECVD-SiNx:H films were investigated by varying the deposition and annealing conditions to optimize for the application in silicon solar cells. By varying the gas ratio (ammonia to silane), the silicon nitride films of refractive indices 1.85 - 2.45 were obtained. The film deposited at $450^{\circ}C$ showed the best carrier lifetime through the film deposition rate was not encouraging. The film deposited with the gas ratio of 0.57 showed the best carrier lifetime after annealing at a temperature of $800^{\circ}C$. The single crystalline silicon solar cells fabricated in conventional industrial production line applying the optimized film deposition and annealing conditions on large area substrate of size $125mm{\times}125mm$ (pseudo square) was found to have the conversion efficiencies as high as 17.05 %. Low cost and high efficiency silicon solar cells fabrication sequence has also been explained in this paper.

• Current Photovoltaic Research
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• v.6 no.3
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• pp.86-90
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• 2018

To generate more current in crystalline silicon solar cells, surface texturing is adopted by reducing the surface reflection. Conventionally, random pyramid texturing by the wet chemical process is used for surface texturing in crystalline silicon solar cell. To achieve higher efficiency of solar cells, well ordered inverted pyramid texturing was introduced. Although its complicated process, superior properties such as lower reflectance and recombination velocity can be achieved by optimizing the process. In this study, we investigated optical and passivation properties of inverted pyramid texture. Lifetime, implied-Voc and reflectance were measured with different width and size of the texture. Also, effects of chemical rounding at the valley of the pyramid were observed.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.347.1-347.1
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• 2016

Screen printing is commonly used to form the electrode for crystalline silicon solar cells. However, it has caused high resistance and low aspect ratio, resulting in decrease of conversion efficiency. Accordingly, Ni/Cu/Ag plating method could be applied for crystalline silicon solar cells to reduce contact resistance. For Ni/Cu/Ag plating, laser ablation process is required to remove anti-reflection layers prior to the plating process, but laser ablation results in surface damage and then decrease of open-circuit voltage and cell efficiency. Another issue with plating process is ghost plating. Ghost plating occurred in the non-metallized region, resulting from pin-hole in anti-reflection layer. In this paper, we investigated the effect of Ni/Cu/Ag plating on the electrical properties, compared to screen printing method. In addition, phosphoric acid layer was spin-coated prior to laser ablation to minimize emitter damage by the laser. Phosphorous elements in phosphoric acid generated selective emitter throughout emitter layer during laser process. Then, KOH treatment was applied to remove surface damage by laser. At this step, amorphous silicon formed by laser ablation was recrystallized during firing process and remaining of amorphous silicon was removed by KOH treatment. As a result, electrical properties as Jsc, FF and efficiency were improved, but Voc was lower than screen printed solar cells because Voc was decreased due to surface damage by laser process. Accordingly, we expect that efficiency of solar cells could be improved by optimization of the process to remove surface damage.