• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.139-143
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• 2017

N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using $a-SiO_X:B$), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into $SiO_2$ phase by FTIR and BRL. The $a-SiO_X:B$ layer is deposited by PECVD using $SiH_4$, $B_2H_6$, $H_2$, $CO_2$ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing $SiH_4$ and $B_2H_6$. When $a-SiO_X:B$ is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.77-79
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• 2009

Amorphous/crystalline silicon heterojunction solar cells, TCO/a-Si:H (p)/c-Si(n)/a-Si:H(n)/Al, are investigated. The influence of various parameters for the front structures was studied. We used thin (10 nm) a-Si:H(p) layers of amorphous hydrogenated silicon are deposited on top of a thick ($500{\mu}m$) crystalline c-Si wafer. This work deals with the influence of the a-Si:H(p) doping concentration on the solar cell performance is studied.

• Journal of the Korean Electrochemical Society
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• v.13 no.1
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• pp.10-18
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• 2010

Nanostructured metal oxides have been widely used in the research fields of photoelectrochemistry, photochemistry and opto-electronics. Dye-sensitized solar cell is a typical example because it is based on nanostructured $TiO_2$. Since the discovery of dye-sensitized solar cell in 1991, it has been considered as a promising photovoltaic solar cell because of low-cost, colorful and semitransparent characteristics. Unlike p-n junction type solar cell, dye-sensitized solar cell is photoelectrochemical type and is usually composed of the dye-adsorbed nanocrystalline metal oxide, the iodide/tri-iodide redox electrolyte and the Pt and/or carbon counter electrode. Among the studied issues to improve efficiency of dye-sensitized solar cell, nanoengineering technologies of metal oxide particle and film have been reviewed in terms of improving optical property, electron transport and electron life time.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.336-340
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• 2012

Wide band gap p-type hydrogenated amorphous silicon oxide (a-SiO:H) buffer layer has been used at the interface of transparent conductive oxide (TCO) and hydrogenated amorphous silicon (a-Si:H) p-type layer of a p-i-n type a-Si:H solar cell. Introduction of 5 nm thick buffer layer improves in blue response of the cell along with 0.5% enhancement of photovoltaic conversion efficiency (η). The cells with buffer layer show higher open circuit voltage (Voc), fill factor (FF), short circuit current density (Jsc) and improved blue response with respect to the cell without buffer layer.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.204-205
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• 2011

In thin film silicon solar cells, p-i-n structure is adopted instead of p/n junction structure as in wafer-based Si solar cells. PECVD is a most widely used thin film deposition process for a-Si:H or ${\mu}c$-Si:H solar cells. For best performance of thin film silicon solar cell, the dopant profiles at p/i and i/n interfaces need to be as sharp as possible. The sharpness of dopant profiles can easily achieved when using multi-chamber PECVD equipment, in which each layer is deposited in separate chamber. However, in a single-chamber PECVD system, doped and intrinsic layers are deposited in one plasma chamber, which inevitably impedes sharp dopant profiles at the interfaces due to the contamination from previous deposition process. The cross-contamination between layers is a serious drawback of a single-chamber PECVD system in spite of the advantage of lower initial investment cost for the equipment. In order to resolve the cross-contamination problem in single-chamber PECVD systems, flushing method of the chamber with NH3 gas or water vapor after doped layer deposition process has been used. In this study, a new plasma process to solve the cross-contamination problem in a single-chamber PECVD system was suggested. A single-chamber VHF-PECVD system was used for superstrate type p-i-n a-Si:H solar cell manufacturing on Asahi-type U FTO glass. A 80 MHz and 20 watts of pulsed RF power was applied to the parallel plate RF cathode at the frequency of 10 kHz and 80% duty ratio. A mixture gas of Ar, H2 and SiH4 was used for i-layer deposition and the deposition pressure was 0.4 Torr. For p and n layer deposition, B2H6 and PH3 was used as doping gas, respectively. The deposition temperature was $250^{\circ}C$ and the total p-i-n layer thickness was about $3500{\AA}$. In order to remove the deposited B inside of the vacuum chamber during p-layer deposition, a high pulsed RF power of about 80 W was applied right after p-layer deposition without SiH4 gas, which is followed by i-layer and n-layer deposition. Finally, Ag was deposited as top electrode. The best initial solar cell efficiency of 9.5 % for test cell area of 0.2 $cm^2$ could be achieved by applying the in-situ plasma cleaning method. The dependence on RF power and treatment time was investigated along with the SIMS analysis of the p-i interface for boron profiles.

• Transactions on Electrical and Electronic Materials
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• v.18 no.2
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• pp.70-73
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• 2017

We investigated n-i-p type single junction hydrogenated amorphous silicon oxide solar cells. These cells were without front surface texture or back reflector. Maximum power point efficiency of these cells showed that an optimized device structure is needed to get the best device output. This depends on the thickness and defect density ($N_d$) of the active layer. A typical 10% photovoltaic device conversion efficiency was obtained with a $N_d=8.86{\times}10^{15}cm^{-3}$ defect density and 630 nm active layer thickness. Our investigation suggests a correlation between defect density and active layer thickness to device efficiency. We found that amorphous silicon solar cell efficiency can be improved to well above 10%.

• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.1
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• pp.15-22
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• 1977

We have obtained a violet-sensitive photocell as a part of the developing project on such type of solar cell. The photocell has the structure of SnO2-SiO2-Si MOS coupled on Si n-p homojuction. It is not relevant to use as a solar cell because of its small photovoltaic power(0.25V, 150$mutextrm{A}$), however, since the spectral response of the cell is shifted toward the violet band region and its switching speed is fairly high in comparison with those of the Si p-n homojunction type solar cell, it is expected that we will be able to find mere novel utilities than the ordinary silicon photocell.

• Korean Journal of Materials Research
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• v.30 no.5
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• pp.262-266
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• 2020

In this paper, we investigated the effect of the passivation stack with Al₂O₃, hydrogenated silicon nitride (SiN_x:H) stack and Al₂O₃, silicon oxynitride (SiON_x) stack in the n type bifacial solar cell on monocrystalline silicon. SiNx:H and SiON_x films were deposited by plasma enhanced chemical vapor deposition on the Al₂O₃ thin film deposited by thermal atomic layer deposition. We focus on passivation properties of the two stack structure after laser ablation process in order to improve bifaciality of the cell. Our results showed SiN_x:H with Al₂O₃ stack is 10 mV higher in implied open circuit voltage and 60 ㎲ higher in minority carrier lifetime than SiON_x with Al₂O₃ stack at Ni silicide formation temperature for 1.8% open area ratio. This can be explained by hydrogen passivation at the Al₂O₃/Si interface and Al₂O₃ layer of laser damaged area during annealing.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.39-43
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• 2017

It was confirmed that the silicon thin films fabricated on the p-Si (100) substrates by using DIPAS (DiIsoPropylAminoSilane) and TDMA-Sb (Tris-DiMethylAminoAntimony) sources by RPCVD method were amorphous and n-type silicon. The fabricated amorphous n-type silicon films had electron carrier concentrations and electron mobilities ranged from $6.83{\times}10^{18}cm^{-3}$ to $1.27{\times}10^{19}cm^{-3}$ and from 62 to $89cm^2/V{\cdot}s$, respectively. The ideality factor of the pn junction diode fabricated on the p-Si (100) substrate was about 1.19 and the efficiency of the fabricated pn solar cell was 10.87%.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.46-51
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• 2023

We investigated the MoS₂ thin film layer by thermolytic deposition and applied it to the silicon solar cells. MoS₂ thin films were made by two methods of dipping and spin coating of (NH₄)₂MoS₄ precursor solution. We implemented two types of substrates of microtextured and nano-microtextured 6-in. Si pn junction wafers. The fabricated MoS₂ thin film layer was analyzed, and solar cells were fabricated by applying the standard silicon solar cell process. The MoS₂ thin film layer of sulfur-deficient form was deposited on the n-type emitter layer, and electrons, which are minority carriers, were well transported at the interface and exhibited photovoltaic solar cell characteristics. The cell efficiencies were achieved at 5% for microtextured wafers and 2.56% for nano-microtextured wafers.