• Current Photovoltaic Research
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• 제2권4호
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• pp.152-156
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• 2014

We report hybrid solar cells fabricated with polymer/fullerene bulk heterojunction layers that contain inorganic nanocrystals synthesized by in-situ reaction in the presence of polymer chains. The inorganic (cadmium sulfide) nanocrystal ($CdS_{NC}$) was generated by the reaction of cadmium acetate and sulfur by varying the reaction time up to 30 min. The synthesized $CdS_{NC}$ showed a rectangular flake shape, while the size of $CdS_{NC}$ reached ca. 150 nm when the reaction time was 10 min. The performance of hybrid solar cells with $CdS_{NC}$ synthesized for 10 min was better than that of a control device, whereas poor performances were measured for other hybrid solar cells with $CdS_{NC}$ synthesized for more than 10 min.

• 태양에너지
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• 제8권1호
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• pp.41-48
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• 1988

Heterojunction solar cells of $n-Cd_{1-x}Zn_xS/p-Si$ were fabricated by solution growth technique. The crystal structure, spectral response, surface morphology, and I-V characteristics of the $n-Cd_{1-x}Zn_xS/p-Si$ heterojunction solar cells were studied. The $Cd_{1-x}Zn_xS$ layer deposited on a silicon substrate (111) were found to be a cubic structure with the crystal orientation (111), (220) of the CdS and to be a hexagonal structure with crystal orientation (100) of the ZnS. The open-circuit voltage, short-circuit current, fill factor, and conversion efficiency of $n-Cd_{1-x}Zn_xS/p-Si$ heterojunction solar cell under $100mW/cm^2$ illumination were found to be 0.43V, 38mA. 0.76, and 12.4%, respectively.

• Current Photovoltaic Research
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• 제1권2호
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• pp.73-81
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• 2013

Heterojunction with Intrinsic Thin-layer (HIT) solar cells are currently an important subject in industrial trends for thinner solar cell wafers due to the low-temperature of production processes, which is around $200^{\circ}C$, and due to their high-efficiency of 24.7%, as reported by the Panasonic (Sanyo) group. The use of thinner wafers and the enhancement of cell performance with fabrication at low temperature have been special interests of the researchers. The fundamental understanding of the band bending structures, choice of materials, fabrication process, and nano-scale characterization methods to provide necessary understanding of the interface passivation mechanisms, emitter properties, and requirements for transparent oxide conductive layers is presented in this review. This information should be used for the performance characterization of the developing technologies for HIT solar cells.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.289-290
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• 2006

We report a study of Zn(S)Se/GaAs heterojunction solar cells grown by molecular beam epitaxy (MBE). Zn(S)Se/GaAs heterostructures prepared under different conditions were characterized in-situ by reflection high-energy electron diffraction (RHEED). Structural and electrical properties were investigated with double crystal X-ray diffraction and current-voltage characteristics, respectively. The fabricated $n-ZnS_{0.07}Se_{0.93}/p-GaAs$ solar cell (SC #2) exhibited open circuit voltage($V_{oc}$) of 0.37 V, short circuit current($I_{sc}$) of $1.7{\times}10^{-2}$ mA, fill factor of 0.62 and conversion efficiency of 7.8 % under 38.5 $mW/cm^2$ illumination.

• 한국전기전자재료학회논문지
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• 제37권4호
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• pp.439-444
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• 2024

This study investigates the post-thermal treatment effects on the efficiency of silicon heterojunction solar cells, specifically examining the influence of annealing on p-type microcrystalline silicon oxide and ITO thin films. By assessing changes in carrier concentration, mobility, resistivity, transmittance, and optical bandgap, we identified conditions that optimize these properties. Results reveal that appropriate annealing significantly enhances the fill factor and current density, leading to a notable improvement in overall solar cell efficiency. This research advances our understanding of thermal processing in silicon-based photovoltaics and provides valuable insights into the optimization of production techniques to maximize the performance of solar cells.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.466.2-466.2
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• 2014

The Quantum dot (QD) solar cells have been under active research due to their high light harvesting efficiencies and low fabrication cost. In spite of these advantages, there have been some problems on the charge collection due to the limitation of the diffusion length. The modification of advanced nanostructure is capable of solving the charge collection problem by increasing diffusion length of electron. One dimensional nanomaterials such as nanorods, nanowires, and nanotubes may enhance charge collection efficiency in QD solar cells. In this study, we synthesized $TiO_2$ anatase nanorod arrays with length of 200 nm by two-step sol-gel method. The morphology and crystal structure for the nanorod were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The anatase nanorods are single-crystalline and possess preferred orientation along with (001) direction. The photovoltaic properties for the heterojunction structure QD solar cells based on the anatase nanorod were also characterized. Compared with conventional $TiO_2$ nanoparticle based QD solar cells, these nanostructure solar cells exhibited better charge collection properties due to long life time measured by transient open circuit studies. Our findings demonstrate that the single crystalline anatase nanorod arrays are promising charge transport semiconductors for heterojunction QD solar cells.

• 한국재료학회지
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• 제21권6호
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• pp.341-346
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• 2011

In this study, we inserted a Zn buffer layer into a AZO/p-type a-si:H layer interface in order to lower the contact resistance of the interface. For the Zn layer, the deposition was conducted at 5 nm, 7 nm and 10 nm using the rf-magnetron sputtering method. The results were compared to that of the AZO film to discuss the possibility of the Zn layer being used as a transparent conductive oxide thin film for application in the silicon heterojunction solar cell. We used the rf-magnetron sputtering method to fabricate Al 2 wt.% of Al-doped ZnO (AZO) film as a transparent conductive oxide (TCO). We analyzed the electro-optical properties of the ZnO as well as the interface properties of the AZO/p-type a-Si:H layer. After inserting a buffer layer into the AZO/p-type a-Si:H layers to enhance the interface properties, we measured the contact resistance of the layers using a CTLM (circular transmission line model) pattern, the depth profile of the layers using AES (auger electron spectroscopy), and the changes in the properties of the AZO thin film through heat treatment. We investigated the effects of the interface properties of the AZO/p-type a-Si:H layer on the characteristics of silicon heterojunction solar cells and the way to improve the interface properties. When depositing AZO thin film on a-Si layer, oxygen atoms are diffused from the AZO thin film towards the a-Si layer. Thus, the characteristics of the solar cells deteriorate due to the created oxide film. While a diffusion of Zn occurs toward the a-Si in the case of AZO used as TCO, the diffusion of In occurs toward a-Si in the case of ITO used as TCO.

• 한국전기전자재료학회논문지
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• 제29권6호
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• pp.376-379
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• 2016

In this paper, the efficiency improvement of the heterojunction with intrinsic thin layer (HIT) solar cells is obtained by optimization process of p-type a-SiC:H as emitter. The optoelectronic of p-type a-SiC:H layers including the optical band-gap and conductivity under the methane gas content variation is conducted in detail. A significant increase in the Jsc by $1mA/cm^2$ and Voc by 30 mV are attributed to enhanced photon-absorption due to broader band-gap of p-a-SiC:H and reduced band-offsets at p-side interface, respectively of HIT solar cells.

• 한국전기전자재료학회논문지
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• 제30권3호
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• pp.192-197
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• 2017

Hydrogenated Amorphous Silicon (a-Si:H) is used as an emitter layer in HIT (heterojunction with Intrinsic Thin layer) solar cells. Its low band gap and low optical properties (low transmittance and high absorption) cause parasitic absorption on the front side of a solar cell that significantly reduces the solar cell blue response. To overcome this, research on CSC (carrier Selective Contacts) is being actively carried out to reduce carrier recombination and improve carrier transportation as a means to approach the theoretical efficiency of silicon solar cells. Among CSC materials, molybdenum oxide ($MoO_x$) is most commonly used for the hole transport layer (HTL) of a solar cell due to its high work function and wide band gap. This paper analyzes the electrical and optical properties of $MoO_x$ thin films for use in the HTL of HIT solar cells. The optical properties of $MoO_x$ show better performance than a-Si:H and ${\mu}c-SiO_x:H$.

• E2M - 전기 전자와 첨단 소재
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• 제8권4호
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• pp.406-412
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• 1995

A n-CdS thin films were evaporated by thermal evaporation method and their structure, optical transmission spectra and electrical characteristics were investigated. The photovoltaic characteristics of solar cells which were fabricated in optimum conditions measured. The evaporated CdS thin films showed in hexagonal structure and above 80% of optical transmission spectra regardless of impurity doping. The high quality thin films could be obtained at 150.deg. C temperature of substrate, which is useful for solar cell window layer with low resistivity of 6*10$\^$-2/(.ohm.-cm) by In doping We measured the electrical and optical characteristics of the n-CdS/p-InP heterojunction solar cells. The most efficient photovoltaic characteristics of heterojunction solar cells had the open circuit voltage of 0.66V, short circuit current density of 13.85mA/cm$\^$2/, fill factor of 0.576 and conversion efficiency of 8.78% under 60mW/cm$\^$2/ illumination.