Silicon Surface Modification Using Alkaline and Acidic Solutions for Solar Cell Applications

Suresh Kumar Dhungel,Seungyong Han,Hongrae Kim,Duy Phong Pham,Youngkuk Kim,Junsin Yi 한국신재생에너지학회 2022 AFORE Vol.2022 No.9

A Brief Review of III-V /Silicon Tandem Solar Cells

Suresh Kumar Dhungel,Youngkuk Kim,Junsin Yi 한국신재생에너지학회 2022 한국신재생에너지학회 학술대회논문집 Vol.2022 No.4

Double-Layer Antireflection Coating of MgF2 SiNx for Crystalline Silicon Solar Cells

Suresh Kumar Dhungel,이준신,JINSU Yoo,김경해,SOMNATH GHOSH,정성욱 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.3

Single layer antireflection coatings are not able to cover a broad range of the solar spectrum. This research investigated changes in the performance parameters of crystalline silicon solar cells caused by a thin film of magnesium fluoride (MgF2) deposited on top of a silicon nitride (SiNx) film already deposited on the emitter layer of a solar cell. The MgF2 film depositions on crystalline cells of large area (125 mm × 125 mm) were carried out by using thermal evaporation under high vacuum ( 10−6 Torr) with a special mask to protect the front metal contact on the busbars after cell fabrication. Significant improvements in the conversion eciency (E) and the short-circuit current (Isc) of the cells were obtained after deposition of the MgF2 layer. Comparison of the unscaled quantum eciencies (QE) before and after MgF2 deposition showed a significant improvement in spectral response, especially in the wavelength range above 700 nm. The theoretical reflectance of the surface with a double-layer antireflection (DLAR) coating, as obtained by simulation, was found to be in agreement with the experimentally measured surface reflectance pattern. Single and multicrystalline silicon solar cells with respective conversion eciencies of 17 and 16 % were fabricated with a conventional solar cell fabrication line.

International Collaboration for High-Efficiency III-V//Si Tandem Solar Cells

Suresh Kumar Dhungel,Somin Park,Seungyong Han,Duy Phong Pham,Youngkuk Kim,Junsin Yi 한국신재생에너지학회 2022 AFORE Vol.2022 No.9

Novel low cost chemical texturing for very large area industrial multi-crystalline silicon solar cells

Gangopadhyay, U,Dhungel, S K,Kim, K,Manna, U,Basu, P K,Kim, H J,Karunagaran, B,Lee, K S,Yoo, J S,Yi, J Institute of Physics 2005 Semiconductor science and technology Vol.20 No.9

<P>Multi-crystalline silicon surface etching without grain-boundary delineation is a challenging task for the fabrication of high efficiency solar cells. The use of sodium hydroxide–sodium hypochlorite (NaOH–NaOCl) solution for texturing a multi-crystalline silicon wafer surface in a solar cell fabrication line is reported in this paper. The optimized etching solution of NaOH–NaOCl does not have any effect on multi-crystalline silicon grain boundaries and it also has excellent isotropic etch characteristics, which ultimately helps to achieve higher values of performance parameters, especially the open circuit voltage (<I>V</I><SUB>oc</SUB>) and fill factor (FF), than those in the case of conventional silicon texturing. Easy control over the reaction of the NaOH–NaOCl solution is also one of the major advantages due to which sophistication in controlling the temperature of the etching bath is not required for the industrial batch process. The FTIR analysis of the silicon surface after etching with the current approach shows the formation of Si–Cl bonds, which improves the quality of the diffused junction due to chlorine gettering during diffusion. We are the first to report 14–14.5% efficiency of very large area (150 mm ? 150 mm) multi-crystalline silicon solar cells using a NaOH–NaOCl texturing approach in an industrial production line with a yield greater than 95%.</P>

태양전지 응용을 위한 PECVD 실리콘 질화막 증착 및 열처리 최적화

류진수,Kumar Dhungel,이준신 대한전기학회 2006 전기학회논문지C Vol.55 No.12C

- 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 450oC showed the best carrier lifetime though 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 800oC. 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 125 mm×125 mm (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.

태양전지 응용을 위한 PECVD 실리콘 질화막 증착 및 열처리 최적화

Yoo, Jin-Su,Dhungel Suresh Kumar,Yi, Jun-Sin 대한전기학회 2006 전기학회논문지C Vol.55 No.12

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.

태양전지 응용을 위한 PECVD 실리콘 질화막 증착 및 열처리 최적화

柳鎭洙(Jinsu Yoo),Kumar Dhungel,李準信(Junsin Yi) 대한전기학회 2006 전기학회논문지C Vol.55 No.12

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°C showed the best carrier lifetime though 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℃. 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 125 ㎜×125 ㎜ (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.

실리콘 태양전지 제조공정과 열화의 상관관계 분석

차예원,Suresh Kumar Dhungel,이준신 한국전기전자재료학회 2023 전기전자재료학회논문지 Vol.36 No.1

In a solar cell, degradation refers to the decrease in performance parameters caused by defects originated due to various causes. During the fabrication process of solar cells, degradation is generally related to the processes such as passivation or firing. There exist sources of many types of degradation; however, the exact cause of Light and elevated Temperature Induced Degradation (LeTID) is yet to be determined. It is reported that the degradation and the regeneration occur due to the recombination of hydrogen and an arbitrary substance. In this paper, we report the deposition of Al2O3 and SiNX on silicon wafers used in the Passivated Emitter and Rear Contact (PERC) solar structure and its degradation pattern. A higher degradation rate was observed in the sample with single layer of Al2O3 only, which indicates that the degradation is affected by the presence or the absence of a passivation thin film. In order to alleviate the degradation, optimization of different steps should be carried out in consideration of degradation in the solar cell fabrication process.

실리콘 태양전지 최적설계에 관한 연구

류진수,Suresh Kumar Dhungel,이준신,문상일,김경해 대한전기학회 2004 전기학회논문지C Vol.53 No.4(C)

In this work, we used the PC1D simulator for simulation of solar cell and examined the effect of front-back surface recombination velocity, minority carrier diffusion length, junction depth and emitter sheet-resistance. As the effect of base thickness, the efficiency decreased by the increase in series resistance with the increase of the thickness and found decrease in efficiency by decrease of the current as the effect of the recombination. Also, as the effect of base resistivity, the efficiency increased somewhat with the decrease in resistivity, but when the resistivity exceeded certain value, the efficiency decreased as a increase in the recombination ratio. The optimum efficiency was obtained at the resistivity 0.5 Ω-cm, and thickness 100 ㎛. We have successfully achieved 10.8% and 13.7% efficiency large area(103mm × 103mm) mono-crystalline silicon solar cells without and with PECVD silicon nitride antireflection coating.