조성비 변화에 의한 CIGS박막 특성에 관한 연구

추순남,박정철,Chu, Soon-Nam,Park, Jung-Cheul 한국정보통신학회 2012 한국정보통신학회논문지 Vol.16 No.10

본 논문은 동시진공증발법(co-evaporation method)으로 CIGS 박막(thin film)을 제작을 하였다. 제작과정 중 기판온도(substrate temperature)변화와 Ga/(In+Ga) 조성비(composition ratio) 변화에 따른 저항율(resistivity) 및 흡수스펙트럼(absorbance spectra)을 측정하였다. 기판온도가 상승하면 저항율이 감소하였으며, Ga/(In+Ga) 조성비가 0.30에서 0.72까지 증가됨에 따라 밴드갭(band gap)이 1.26eV, 1.30eV, 1.43eV,1.47eV로 증가됨을 알 수 가 있었다. 동일한 조건에서 조성비를 증가하므로써 두께가 증가되었으며 저항율은 감소하였다. 본 실험을 통하여 CIGS 박막을 제작하면 광흡수률(optical absorbance ratio) 및 광전류(optical current)가 증가 될 것으로 예측할 수가 있다. In this paper, we produced CIGS thin film by co-evaporation method. During the process, substrate temperature and Ga/(In+Ga) composition ratio was altered to observe the change of resistivity and absorbance spectra measurements. As substrate temperature increased, resistivity decreased and as Ga/(In+Ga) composition ratio increased from 0.30 to 0.72, band gap also increased with the range of 1.26eV, 1.30eV, 1.43eV, 1.47eV. With the constant condition of composition ratio, resistivity decreased with increased thickness of the thin film. On this experiment, we assumed that optical absorbance ratio and optical current will be increased with CIGS thin film fabrication.

열처리에 의한 Cu(In,Ga)Se₂ 태양전지 특성에 관한 연구

추순남,박정철,Chu, Soon-Nam,Park, Jung-Cheul 한국정보통신학회 2013 한국정보통신학회논문지 Vol.17 No.12

본 논문은 동시진공증발법으로 제작된 시편을 $500^{\circ}C$에서 열처리한 시편은 기공이 많이 발생되어 결정결함이 발생 되었어 열처리 시 Se분위기하에서 실행을 해야 된다는 것을 알 수가 있었다. 기판온도를 $430^{\circ}C$, $460^{\circ}C$, $480^{\circ}C$, $500^{\circ}C$로 변화주어 제작된 시편을 열처리 한 결과 결정입자 크기가 증가되어 밀도가 향상되었다. 그리고 XRD 분석결과, 열처리 후에 Cu2Se상이 제거되었으며 열처리 전 후의 흡수지수는 큰 변화가 없었다. 이것은 흡수지수는 열처리보다 시편 두께에 의해 결정된다는 것을 알 수가 있었다. In this paper, we prepared the samples with the heat-treated substrate by means of co-evaporation method. The samples prepared with heat-treated substrate of $500^{\circ}C$showed the vacancy on the surface, and it could be prevented by Se ambient condition. The samples prepared with variable heat-treated substrates such as $430^{\circ}C$, $460^{\circ}C$, $480^{\circ}C$ and $500^{\circ}C$ showed the increase of grain resulted to the increase of the density. Based on the XRD analysis, the heat treatment could remove the Cu2Se phase of the samples, but it didn't affect the absorption index of the samples. We, therefore, conclude the absorption index is not affected by heat treatment and is controlled by the thickness of the sample.

The Effect of Chrome Oxide on the Threshold Voltage of ZnO Varistor

추순남 경원전문대학 1995 論文集 Vol.17 No.2

ZnO바리스터의 문턱전압(절연파괴 개시전압)은 바리스터의 규정전압을 평가하는데 있어서 매우 중요한 요소이다. Bi산화물를 기본조성으로 한 ZnO바리스터의 문턱전압에 미치는 크롬산화물의 영향에 대하여 조사하였다. 전자주사현미경의 관찰로부터 크롬산화물에 따른 결정립과 결정입계의 변화를 관찰하였다. 문턱전압은 입계층 상태와 입자크기에 의존하게 됨을 알았다. ZnO 바리스터의 정전용량과 입자크기는 크롬산화물의 증가와 함께 감소 되었다. 그리고 겉보기 문턱전압의 증가는 ZnO 입자내부에 존재하는 공핍층 도너밀도의 감소특성에 기인되었다. 이들의 결과들은 C-V특성, 절연파괴전압 그리고 미세구조사진으로부터 얻어졌다. Threshold voltage ZnO varistor, critical point of breakdown voltage, is important electrical parameter that is necessary for quantitative evaluation of the rated varistor voltage. The effect of Cr₂O₃ additive on the threshold voltage characteristics of Bi-based ZnO ceramic varistor was studies. From the observation of Scanning Electron Microscopy, grain size and grain boundary according to Cr₂O₃ content was investigated. The thresh-old voltage of the ZnO ceramics was dominated by grain boundary interface states and grain size. The capacitance and grain size decreased with increasing Cr₂O₃ content, It is found that the increases in the apparent threshold voltage is associated with the lowered donor concentration in depletion region of ZnO grain. These result are obtained by measuring C-V characteristics, breakdown voltage at the current density 1O A/㎠ and micro-structure of ZnO ceramics.

Preparation of YBa2Cu3Ox Superconductor Prepared with Additives of PbO and Ag2O

추순남,박정철,전용우 한국전기전자재료학회 2009 Transactions on Electrical and Electronic Material Vol.10 No.1

The improvement of preparation process of YBa2Cu3Ox superconductor and its conducting properties is important for practical applications. In this study, the additives such as Ag2O and PbO were used to improve the preparation conditions of YBa2Cu3Ox superconducting bulk samples and the properties of YBa2Cu3Ox superconductors prepared with powders using sol-gel method and solid state reaction method were studied. The effects of the different powders and the additives to the density, grain alignment, and porosity of samples, that affect the critical current density of superconductor, also have been investigated. It is found that the properties of YBa2Cu3Ox prepared with sol-gel synthesized powder and the additives showed better superconductivities than those of conventionally prepared superconductors.

반응성 스퍼터링법으로 AI/AIN/GaAs 커패시터 제조시 (NH₄)₂S 처리에 따른 전기적 특성

추순남,권정열,박정철,이헌용,Chu, Soon-Nam,Kwon, Jung-Youl,Park, Jung-Cheul,Lee, Heon-Yong 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.1

In MIS capacitor structure, we have studied the electrical properties in Ammonium Sulfide solution treatment while AIN thin film as a insulator is being formed by reactive sputtering method. The deposition process conditions of AIN thin film we temperature $250^{\circ}C$, DC Power 150 W, pressure 5 mTorr and 8 sccm(Ar : 4 sccm, $N_{2}$ : 4 sccm). The surface of GaAs was treated with Ammonium Sulfide solution, it was shown the leakage current was less than $10^{-8}\;A/cm^{2}$. The deep depletion phenomena of inverse area with treating Ammonium Sulfide solution in C-V analysis was improved as compared the condition of without Ammonium Sulfide solution and hysteresis property as well.

The Effect of Additives on the Microstructure and Electrical Properties of ZnO Ceramics

추순남 경원전문대학 1994 論文集 Vol.16 No.2

본 연구에서는 0.5mo1e%의 각종 dopants가 첨가된 2성분계 ZnO세라믹스에 있어서 비오옴적 전류-전압특성과 복합임피던스 특성에 대하여 연구 조사하였다. 전기적 특성은 도전성의 ZnO 결정립으로 둘러 쌓인 비도전성인 결정입계 구조를 갖는 ZnO 세라믹스의 미세구조에 직접적으로 관련되었다. 전자주사현미경을 사용하여 관찰한 미세구조 사진으로부터 결정입계의 연속상을 관찰할 수 있었다. 2성분계 ZnO 세라믹스의 전기적 특성의 실험결과로부터 비옴성의 특성은 결정입계층에 의존되고 있음을 보여주었다. 복합 임피던스 측정으로부터는 결정입계의 임피던스 존재를 확인하였고, 결정입계 임피던스의 크기에 따라서 복합임피던스의 모양변화를 확인하였다. The nonohmic current-voltage characteristics and complex impedance plot of sintered binary ZnO ceramics containing 0.5mo1e% additives were investigated. Electrical properties are related directly to the microstructure, which consist of conductive ZnO grains separated by thin nonconductive boundary layer. The microstructure was observed directly by Scanning Electron Microscopy, Proving the existence of continuous intergranular phase. Experiments with binary ZnO ceramics was showed that the grain boundary layer alon can exhibit nonohmic characteristics. Complex impedance measurements indicate the pos-sible presence of grainboundary impedance. The shape of complex impedance plots depend on grainboundary impedance.

화재감지센서 활용을 위한 적층형 PTC 서미스터의 특성에 관한 연구

추순남,백동현 한국화재소방학회 2005 한국화재소방학회논문지 Vol.19 No.2

This dissertation is about the development of PTC(Positive Temperature Coefficient) thermistor by composition method. A multilayer-type PTC samples were fabricated under optimal conditions after setting the experimental composition equation as (0.90Ba+0.05Sr+0.05Ca)TiO3+0.01TiO3+0.01SiO2 + 0.0008MnO2+0.0018Nb2O5 and their testing results were analyzed. The fabrication method of SMD(Surface Mounted Device) multilayer -type sample based on the composition ratio has the advantages in lowering its resistivity at room temperature, considerably, and increasing maximum current level, as needed. Although there is a disadvantage of peak resistivity drop by the multilayer, causing the increasement of thermal capacity, and thereby, increasing the switching delay time, a high applying voltage can increase the peak resistivity and shorten the switching delay time. The voltage-current characteristic showed that the more multilayers increased the initial maximum current and the transition voltage that increased the resistivity abruptly according to the curie point. The element it could be applied with the sensor for the fire detector. 적층형 PTC 서미스터의 특성연구를 위해 (0.90Ba+0.05Sr+0.05Ca)TiO3+0.01TiO3+0.01SiO2+ 0.0008MnO2+0.0018Nb2O5와 같은 실험조성식을 설정한 후 표면실장(SMD) 적층형 PTC 시편을 제작하 였다. 그 결과 상온 비저항 값을 크게 낮출 수 있고 용도에 따라 전류용량을 크게 할 수 있었으나 적층 화로 인해 peak 비저항이 크게 낮아지고 열용량이 커짐으로써 스위칭(switching)시간이 늦어지는 점을 확 인하였다. 전압-전류 특성에서는 적층수가 증가할 수록 초기 최대전류값이 증가하며 큐리점에 대응하여 저 항값이 급격히 커지는 전이전압(전계)도 증가함을 보였다. 그러나 인가전압(전계)을 증가시킬 경우 peak 비 저항값을 높일 수 있어 스위칭시간을 줄일 수 있다. 이 소자는 화재감지기의 센서로 활용될 수 있다.

BTS 방법을 사용한 Low-K 유전체 물질들과 산화막의 Cu 드리프트 확산에 대한 비교 연구

추순남,권정열,김장원,박정철,이헌용,Chu, Soon-Nam,Kwon, Jung-Youl,Kim, Jang-Won,Park, Jung-Cheul,Lee, Heon-Yong 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.2

Advanced back-end processing requires the integration of low-k dielectrics and Cu. However, in the presence of an electric field and a temperature, positive Cu ions may drift rapidly through dielectric and causing reliability problems. Therefore, in this paper, Cu+ drift diffusion in two low-k materials and silicon oxide is evaluated. The drift diffusion is investigated by measuring shifts in the flat band voltage of capacitance-voltage measurements on Cu gate capacitors after bias thermal stressing. The Cu+ drift late in $SiO_{x}C_{y}\;(2.85{\pm}0.03)$ and Polyimide(2.7${\leq}k{\leq}3.0$) is Considerably lower than in thermal oxide.

YBa₂Cu₃Ox 분말과 첨가제 BaPbO₃를 이용한 초전도체 제작

추순남,박정철,Chu, Soon-Nam,Park, Jung-Cheul 한국정보통신학회 2011 한국정보통신학회논문지 Vol.15 No.8

미세 입자 크기를 갖는 $YBa_2Cu_3Ox$(YBCO) 초전도 분말을 이용하여 $BaPbO_3$ 첨가에 따른 $YBa_2Cu_3Ox$ 초전도 벌크의 임계전류를 향상시키는 요소인 시편의 밀도와 결정들의 정렬 상태를 향상시키고, 기공도를 감소시키기 위한 연구를 수행하였다. 졸겔법으로 미세 크기를 갖는 $YBa_2Cu_3Ox$ 초전도 분말을 합성하여 입자의 크기가 0.2~1 ${\mu}m$의 미세한 분포를 갖는 초전도 분말을 사용하고, $YBa_2Cu_3Ox$ 초전도 시편의 입자 성장을 촉진시키고, 기공과 입계간의 약연접을 감소시키기 위하여 금속 물질 및 구조 화합물인 $BaPbO_3$를 10~30 wt%를 첨가하여 시편을 제작하고 특성을 관찰하였다. 나노 크기를 갖는 YBCO 분말과 $BaPbO_3$ 20 wt%를 첨가하여 제작한 $YBa_2Cu_3Ox$ 초전도 시편은 일반적인 벌크 제작법으로 제작된 시편과 비교하여 임계전류가 20% 향상된 4.74A를 얻었다. In this paper, as an attempt to improve the preparation conditions of $YBa_2Cu_3Ox$ superconducting bulk samples, the properties of $YBa_2Cu_3Ox$ superconductor depending on the particle size of YBCO powder and $BaPbO_3$ as an additive have been investigated, and a study on the effects of additive to the density, grain alignment, and porosity of samples that affect the critical current of superconductor has been performed. In order to prepare superconductor, $YBa_2Cu_3Ox$ powder synthesized by sol-gel method, showing a size distribution of 0.2~1 ${\mu}m$ was used. The $BaPbO_3$ added to promote grain growth and to decrease porosities and weak links between grain boundaries of $YBa_2Cu_3Ox$ superconductors. In the samples prepared by sol-gel synthesized powder with 10, 20, and 30 wt% conductive $BaPbO_3$ additives, the sample with 20 wt% $BaPbO_3$ obtained the highest critical current of 4.74 A, showing 20 wt% higher critical current than that with solid state synthesized powder.

화재감지센서 활용을 위한 BaTO₃계 PTC 서미스터의 특성에 관한 연구

추순남,최명규,백동현,박정철 한국화재소방학회 2002 한국화재소방학회논문지 Vol.16 No.4

<TEX>BaTiO$_3$</TEX>계 PTC 서미스터의 조성개발을 위해 (<TEX>Ba$_{0.95-x}$</TEX>S <TEX>$r_{0.05}$</TEX>C <TEX>$a_{x}$</TEX>)<TEX>$TiO_3$</TEX>-<TEX>$0.01TiO_2$</TEX>-<TEX>$0.01SiO_2$</TEX>-<TEX>$\alpha$</TEX><TEX>MnCO_3$</TEX>-<TEX>$\beta$</TEX><TEX>Nb_2$</TEX><TEX>o_{5}$</TEX>와 같은 실험조성식을 설정한 후 최적 조건하에서 적층형 PTC시편을 제작하여 실험하였다. 실험 결과, 시편제조시의 최적 소결온도와 냉각속도는 각각 <TEX>$1350^{\circ}C$</TEX>-2 hour및 <TEX>$100^{\circ}C$</TEX>/h였다. 또한 상온저항을 낮추는 효과가 있는 Dopant로서의 Ca와 Mn 그리고 피크(peak)저항값을 높일 수 있는 Nb를 Ca:5 mol%, Mn:0.08 mol%, Nb:0.18 mol%로 함으로써 비교적 낮은 상온저항과 높은 피크(peak)저항 및 양호한 온도계수 특성이 나타났으며, 화재감지센서로서의 활용 가능성을 확인하였다.다.다. This dissertation is about the development of <TEX>$BaTiO_3$</TEX>-type PTC(Positive Temperature Coefficient) thermistor by composition method. A multilayer-type PTC samples were fabricated under optimal conditions after setting the experimental composition equation as (<TEX>$Ba_{0.95-x}$</TEX>S <TEX>$r_{0.05}$</TEX><TEX>$Ca_{x}$</TEX> )<TEX>$TiO_3$</TEX>-<TEX>$0.01TiO_2$</TEX>-<TEX>$0.01SiO_2$</TEX>-<TEX>$\alpha$</TEX><TEX>$MnCO_3$</TEX>-<TEX>$\beta$</TEX>N <TEX>$b_2$</TEX> <TEX>$O_{5}$</TEX>.) and their testing results were analyzed. The optimal sin-tering and cooling temperatures were 13<TEX>$50^{\circ}C$</TEX> for two hours and <TEX>$100^{\circ}C$</TEX>/h for an hour, respectively; By composing Ca and Mn, dopants to lower the resistivity at room temperature, and Nb, a dopant to raise peak resistivity(Ca:5 mol%, Mn:0.08 mol%, Nb:0.18 mol%), appropriately, a PTC thermistor, having the characteristics of relatively low resistivity at room temperature and high peak resistivity and a good temperature coefficient, has been developed. And we find that it is possible of application for fire detection sensor.r.r.