• Title/Summary/Keyword: Hetero junction

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Investigated properties of Low temperature curing Ag Paste for Silicon Hetero-junction Solar Cell

  • Oh, Donghyun;Jeon, Minhan;Kang, Jiwoon;Shim, Gyeongbae;Park, Cheolmin;Lee, Youngseok;Kim, Hyunhoo;Yi, Junsin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.160-160
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    • 2016
  • In this study, we applied the low temperature curing Ag paste to replace PVD System. The electrode formation of low temperature curing Ag paste for silicon Hetero-junction solar cells is important for improving device characteristics such as adhesion, contact resistance, fill factor and conversion efficiency. The low temperature curing Ag paste is composed various additives such as solvent, various organic materials, polymer, and binder. it depends on the curing temperature conditions. The adhesion of the low temperature curing Ag paste was decided by scratch test. The specific contact resistance was measured using the transmission line method. All of the Ag electrodes were experimented at various curing temperatures within the temperature range of $160^{\circ}C-240^{\circ}C$, at $20^{\circ}C$ intervals. The curing time was also changed by varying the conditions of 10-50min. In the optimum curing temperature $200^{\circ}C$ and for 20 min, the measured contact resistance is $19.61m{\Omega}cm^2$. Over temperature $240^{\circ}C$, confirmed bad contact characteristic. We obtained photovoltaic parameter of the industrial size such as Fill Factor (FF), current density (Jsc), open-circuit voltage (Voc) and convert efficiency of up to 76.2%, 38.1 mA/cm2, 646 mV and 18.3%, respectively.

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The Study on the Improvement of Mechanical Performance due to Change in Temperature and Sputtering by $SiO_2/Ag$ Material of Bonded Dissimilar Materials with Cylindrical Shape (원통형 이종 접합 소재의 $SiO_2/Ag$스퍼터 증착과 온도 변화에 따른 기계적 특성에 관한 연구)

  • Lee, Seung-Hyun;Choi, Seong-Dae;Lee, Jung-Hyong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.3
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    • pp.138-145
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    • 2012
  • The material used in this study is dielectric and ferrite. Because of the unique characteristics of the material, it is easily exposed to external shocks and pressure, which cause damage to the product. However, after being processed under high-temperature environment repeatedly, the mechanical strength of the product is greatly increased due to the change of the electrical properties. In this paper, dielectric and bonded ferrite material was tested for the material properties. The equipment for this experiment was produced and tested to allow Cylindrical and Three-dimensional geometry of the product for the vacuum deposition. For Cylindrical shape of the product, in order to obtain the equivalent film thickness, the device is constructed in a vacuum chamber which gives arbitrary revolving and rotating capability. The electrical performance of the product is obtained through this process as well. However, as mentioned above, with repeating processes under high temperature and exposure to external environment, the product is easy to be broken. This experiment has enabled us to find out a stable condition to apply the communication of the RF high frequency to each of the core elements, such as Ferrite and Dielectric which is then used for the mechanical strength of the Raw material, hetero-junction material, Hetero-junction Ag Coating material and hetero-junction Ag Coating SiO2 Coating material respectively.

Time-Variant Characteristics of Organic Thin Film Solar Cell Devices on Plastic Substrates (플라스틱 기판에 제작된 유기박막태양전지의 출력특성 경시변화)

  • No, Im-Jun;Lee, Sunwoo;Shin, Paik-Kyun
    • Journal of the Korean Vacuum Society
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    • v.22 no.4
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    • pp.211-217
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    • 2013
  • Two types of organic thin film solar cell devices with bulk hetero-junction (BHJ) structure were fabricated on plastic substrates using conjugated polymers of $PCDTBT:PC_{71}BM$ and $PTB7:PC_{71}BM$ blended as active channel layer. Time-variant characteristics of the organic thin film solar cell devices were investigated: short circuit current density ($J_{SC}$); open circuit voltage ($V_{OC}$); ; fill factor (FF); power conversion efficiency (PCE, ŋ). All the performance parameters were degraded by progress of the measurement time, while $V_{OC}$ showed the most drastic decrease with time. Possible factors to cause the time-variant alteration of performance parameters were discussed to be clarified.

Fabrication and Characteristics of Hetero-junction EL Devices Containing Electron Transport Layer and PPV as Emitting Layer (PPV 발광층 및 전자 수송층을 가진 이종 접합구조 EL 소자의 제작 및 특성)

  • Park, Lee Soon;Han, Yoon Soo;Kim, Sung Jin;Shin, Dong Soo;Shin, Won Gi;Kim, Woo Young;Lee, Choong Hun
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.710-714
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    • 1998
  • Organic electroluminescence devices (ELD) with hetero-junction structure were fabricated utilizing poly(p-phenylne vinylene) (PPV) as emitting layer and electron transport layer (ETL). 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) was used as an electron transport agent. Copolymers with stilbene type comonomers, such as poly(styrene-co-PVTS), poly(styrene-co-MeO-PVTS) and poly(styrene-co-MeO-ST) were synthesized to be used as a matrix polymer to disperse electron transport agent (PBD). Among the hetero-junction EL devices fabricated with the above materials, the device with poly(styrene-co-PVTS) as matrix polymer for ETL gave the highest luminance ($120.7cd/m^2$, 13 V). EL devices made with poly(styrene-co-MeO-PVTS) or poly(styrene-co-MeO-ST) matrix exhibited lower luminance than the one with polystyrene matrix and the single layer EL (ITO/PPV/Mg) device.

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A Study on the Performance Improvement for Flexible PCDTBT : PC71BM Organic Thin Film Solar Cell by Ozone Surface Treatment of ITO Electrode (ITO 전극의 오존 표면처리에 의한 플렉시블 PCDTBT : PC71BM 유기박막 태양전지의 성능 개선에 관한 연구)

  • No, Im-Jun;Lim, Young-Taek;Shin, Paik-Kyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.11
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    • pp.104-108
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    • 2012
  • Flexible organic thin film solar cell device with Bulk Hetero-Junction (BHJ) structure was fabricated with blended conjugated polymer of PCDTBT : $PC_{71}BM$ as active layer. Surface of ITO anode for the organic solar cell device was treated with ozone. The organic solar cell device with bare ITO showed short circuit current density ($J_{sc}$) of $8.2mA/cm^2$, open-circuit voltage ($V_{oc}$) of 0.73V, fill factor (FF) of 0.36, and power conversion efficiency (PCE) of 2.16%, respectively. The organic solar cell device with ozone treated ITO anode revealed distinctively improved performance parameters:$J_{sc}$ of $9.8mA/cm^2$, $V_{oc}$ of 0.82V, FF of 0.43, PCE(${\eta}$) of 3.42%.

Bi-directional Two Terminal Switching Device based on SiGe for Spin Transfer Torque (STT) MRAM

  • Yang, Hyung-Jun;Kil, Gyu-Hyun;Lee, Sung-Hyun;Song, Yun-Heub
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.385-385
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    • 2012
  • A two terminal N+/P/N+ junction device to replace the conventional selective transistor was studied as a bilateral switching device for spin transfer torque (STT) MRAM based on 3D device simulation. An N+/P/N+ junction structure with $30{\times}30nm$ area requires bi-directional current flow enough to write a data by a drain induced barrier lowering (DIBL) under a reverse bias at N+/P (or P/N+ junction), and high current on/off ratio of 106. The SiGe materials are widely used in hetero-junction bipolar transistors, bipolar compensation metal-oxide semiconductors (BiCMOS) since the band gap of SiGe materials can be controlled by changing the fraction and the strain epilayers, and the drift mobility is increased with the increasing Ge content. In this work, N+/P/N+ SiGe material based junction provides that drive current is increased from 40 to $130{\mu}A$ by increased Ge content from 10~80%. When Ge content is about 20%, the drive current density of SiGe device substantially increased to 2~3 times better than Si-based junction device in case of 28 nm P length, which is sufficient current to operation of STT-MRAM.

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The reliability physics of SiGe hetero-junction bipolar transistors (실리콘-게르마늄 이종접합 바이폴라 트랜지스터의 신뢰성 현상)

  • 이승윤;박찬우;김상훈;이상흥;강진영;조경익
    • Journal of the Korean Vacuum Society
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    • v.12 no.4
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    • pp.239-250
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    • 2003
  • The reliability degradation phenomena in the SiGe hetero-junction bipolar transistor (HBT) are investigated in this review. In the case of the SiGe HBT the decrease of the current gain, the degradation of the AC characteristics, and the offset voltage are frequently observed, which are attributed to the emitter-base reverse bias voltage stress, the transient enhanced diffusion, and the deterioration of the base-collector junction due to the fluctuation in fabrication process, respectively. The reverse-bias stress on the emitter-base junction causes the recombination current to rise, increasing the base current and degrading the current gain, because hot carriers formed by the high electric field at the junction periphery generate charged traps at the silicon-oxide interface and within the oxide region. Because of the enhanced diffusion of the dopants in the intrinsic base induced by the extrinsic base implantation, the shorter distance between the emitter-base junction and the extrinsic base than a critical measure leads to the reduction of the cut-off frequency ($f_t$) of the device. If the energy of the extrinsic base implantation is insufficient, the turn-on voltage of the collector-base junction becomes low, in the result, the offset voltage appears on the current-voltage curve.

Fabrication and characterization of n-IZO / p-Si and p-ZnO:(In, N) / n-Si thin film hetero-junctions by dc magnetron sputtering

  • Dao, Anh Tuan;Phan, Thi Kieu Loan;Nguyen, Van Hieu;Le, Vu Tuan Hung
    • Journal of IKEEE
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    • v.17 no.2
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    • pp.182-188
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    • 2013
  • Using a ceramic target ZnO:In with In doping concentration of 2%, hetero-junctions of n-ZnO:In/p-Si and p-ZnO:(In, N)/n-Si were fabricated by depositing Indium doped n - type ZnO (ZnO:In or IZO) and Indium-nitrogen co-doped p - type ZnO (ZnO:(In, N)) films on wafers of p-Si (100) and n-Si (100) by DC magnetron sputtering, respectively. These films with the best electrical and optical properties were then obtained. The micro-structural, optical and electrical properties of the n-type and p-type semiconductor thinfilms were characterized by X-ray diffraction (XRD), RBS, UV-vis; four-point probe resistance and room-temperature Hall effect measurements, respectively. Typical rectifying behaviors of p-n junction were observed by the current-voltage (I-V) measurement. It shows fairly good rectifying behavior with the fact that the ideality factor and the saturation current of diode are n=11.5, Is=1.5108.10-7 (A) for n-ZnO:In/p-Si hetero-jucntion; n=10.14, Is=3.2689.10-5 (A) for p-ZnO:(In, N)/n-Si, respectively. These results demonstrated the formation of a diode between n-type thin film and p-Si, as well as between p-type thin film and n-Si..

Design and Fabrication of Ka-band Push-push oscillator Using Dielectric Resonator (유전체 공진기를 이용한 Ka-band용 Push-push 발진기의 설계 및 구현)

  • 김민호;김병희;박천석
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.385-388
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    • 2000
  • In this paper, the Ka-band Dielectric resonator oscillator has been designed and fabricated. The resonator network was simulated using HFSS program. The design method of an oscillator is the small-signal S-parameter design. The Push-push DRO employs a hetero junction FET (NE32484A). The fabricated Push-push DRO shows such characteristics as the phase noise -106 ㏈c/Hz at the 100 ㎑ frequency offset. the output power and fundamental frequency surpression were -6 ㏈m and -29 ㏈c, respectively.

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