자동차용 폐 리튬 이차전지 모듈의 안정적 해체와 알루미늄 박막으로부터 양극활물질의 분리공정 개발

김연정,오인경,홍용표,유건상 대한화학회 2019 대한화학회지 Vol.63 No.6

It has developed a method that can recover efficiently the reproducible resources from the vehicle waste lithium second battery module. Module cell consists of copper thin film, aluminum thin film and diaphragm made with polymer between these thin films. Cell was disassembled completely without any damage in glove box and through several steps. Preferentially, cathode active material was separated from aluminum thin film at heat treatment of 400 oC. The retrieved cathode active material was then obtained as high purity after calcining at 800 oC to remove residual carbon. Based on this study, it was found that rare metals such as Co, Ni, Mn and Li made up of cathode active material could recover above 80% from aluminum thin film. 본 연구는 자동차 폐리튬 이차전지의 모듈로부터 재생할 수 있는 자원을 효율적으로 회수하는 방법을 개발하는 것이다. 모 듈의 셀은 구리 박막, 알루미늄 박막, 그리고 이들 사이는 폴리머 재질의 격막으로 이루어져 있다. 셀은 특별히 제작한 글러브 상 자 안에서 그리고 여러 번의 단계를 거쳐 손상 없이 완전히 해체 하였다. 우선적으로 양극활물질은 400 oC에서 열처리하여 알루 미늄 박막으로부터 분리하였다. 그런 후 분리된 양극활물질은 잔류되어 있는 탄소 성분을 제거하기 위해 800 oC에서의 소성 후 에 최종적으로 높은 순도로 회수되었다. 본 연구 결과를 바탕으로 해서, 알루미늄 박막으로부터 양극활물질을 구성하고 있는 코 발트(Co), 니켈(Ni), 망간(Mn), 리튬(Li)과 같은 희유금속들을 80% 이상 회수할 수 있었다.

Influence of Surface Texturing on the Electrical and Optical Properties of Aluminum Doped Zinc Oxide Thin Films

Lee, Jaeh-Yeong,Shim, Joong-Pyo,Jung, Hak-Kee The Korea Institute of Information and Commucation 2011 Journal of information and communication convergen Vol.9 No.4

An aluminum doped zinc oxide (AZO) film for front contacts of thin film solar cells, in this work, were deposited by r.f. magnetron sputtering, and then etched in diluted hydrochloric acid solution for different times. Effects of surface texturing on the electro-optical properties of AZO films were investigated. Also, to clarify the light trapping of textured AZO film, amorphous silicon thin film solar cells were fabricated on the textured AZO/glass substrate and the performance of solar cells were studied. After texturing, the spectral haze at the visible range of 400 ~750 nm increased substantially with the etching time, without a change in the resistivity. The conversion efficiency of amorphous Si solar cells with textured AZO film as a front electrode was improved by the increase of short-circuit current density ($J_{sc}$), compared to cell with flat AZO films.

Poly-Crystalline Thin-Film by Aluminum Induced Crystallization on Aluminum Nitride Substrate

Muhammad Fahad Bhopal,이두원,이수홍 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.5

Thin-film polycrystalline silicon (pc-Si) on foreign (non-silicon)substrates has been researched by various research groups for theproduction of photovoltaic cells. High quality pc-Si depositionon foreign substrates with superior optical properties isconsidered to be the main hurdle in cell fabrication. Metalinduced crystallization (MIC) is one of the renowned techniquesused to produce this quality of material. In the current study, analuminum induced crystallization (AIC) method was adopted toproduce pc-Si thin-film on aluminum nitride (AlN) substrate by aseed layer approach. Aluminum and a-Si layer were depositedusing an e-beam evaporator. Various annealing conditions wereused in order to investigate the AIC grown pc-Si seed layers forprocess optimization. The effect of thermal annealing on grainsize, defects preferentially crystallographic orientation of thegrains were analyzed. Surface morphology was studied using anoptical microscope. Poly-silicon film with a crystallinity fractionbetween 95-100% and an FWHM between 5-6 cm−1 is achievable at low temperatures and for short time intervals. A grainsize of about 10 micron can be obtained at a low deposition rate on an AIN substrate. Similarly, Focused ion beam (FIB) alsoshowed that at 425 °C sample B and at 400 °C sample A were fully crystallized. The crystalline quality of pc-Si wasevaluated using μ-Raman spectroscopy as a function of annealed conditions and Grazing incidence X-ray diffraction(GIXRD) was used to determine the phase direction of the pc-Si layer. The current study implicates that a poly-silicon layerwith good crystallographic orientation and crystallinity fraction is achievable on AIN substrate at low temperatures and shorttime frames.

Modification of Optical and Mechanical Surface Properties of Sputter-Deposited Aluminum Thin Films through Ion Implantation

Kang, Tae June,Kim, Jeong-Gil,Lee, Ho-Young,Lee, Jae-Sang,Lee, Jae-Hyung,Hahn, Jun-Hee,Kim, Yong Hyup 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.5

Aluminum (Al) thin films are used widely as an electronic material in a variety of applications because of their high conductivity, optical reflectance and low cost. In the present study, helium (He) and nitrogen (N2) ions were implanted in sputter-deposited Al thin films with different doses and energies, and the changes in the film properties, such as the surface roughness, optical reflectance, hardness and Young's modulus, were investigated. The results showed that the implantation of both ions smooth the surface of Al thin films by decreasing the hillock density, resulting in low global surface roughness. In particular, in the case of He ion implantation, the moderated degradation of optical reflectance was observed compared to the film implanted with nitrogen ion. On the other hand, excessive ion implantation increased the local (short-range) surface roughness, which deteriorated the optical reflectance of the Al films. The continuous stiffness measurement technique in nano-indentation showed that ion implantation increased the hardness near the surface. He ion implantation hardened the surface of the Al thin film, and almost 2 times higher surface hardness was achieved with an ion dose of $10^{18}ions/cm^2$ at 40 KeV.

Solution-processed lanthanum-doped Al₂O₃ gate dielectrics for high-mobility metal-oxide thin-film transistors

Kim, Jaeyoung,Choi, Seungbeom,Jo, Jeong-Wan,Park, Sung Kyu,Kim, Yong-Hoon Elsevier 2018 THIN SOLID FILMS - Vol.660 No.-

<P><B>Abstract</B></P> <P>Solution-processed oxide gate dielectrics play an important in thin-film transistors (TFTs), determining their operation voltage, device performance and power consumption. Up to now, various solution-processed oxide gate dielectrics such as aluminum oxide (Al<SUB>2</SUB>O<SUB>3</SUB>) have been surveyed, however, they generally exhibit relatively high leakage current, low dielectric constant, and hysteresis which are unfavorable for stable device operation. Here, we demonstrate solution-processed lanthanum (La)-doped Al<SUB>2</SUB>O<SUB>3</SUB> (LAO) gate dielectrics which exhibit low leakage current density, high dielectric constant, and relatively small frequency-dependent capacitance variation. In order to find the optimal doping concentration of lanthanum in Al<SUB>2</SUB>O<SUB>3</SUB> film, various electrical, morphological, and spectroscopic analyses were carried out. We found that the addition of lanthanum in Al<SUB>2</SUB>O<SUB>3</SUB> film effectively reduced the defective metal hydroxide bonding states within the film and significantly enhanced its dielectric characteristics. At an optimal doping concentration of lanthanum (20 at.%), gate dielectrics showing leakage current density, dielectric constant, and breakdown field of ~10<SUP>−8</SUP> A/cm<SUP>2</SUP> (at 2 MV/cm), 10.5, and >5 MV/cm were obtained. Using the LAO film as a gate dielectric, solution-processed indium-zinc-oxide TFTs having a field-effect mobility of 11.9 cm<SUP>2</SUP>/V-s, subthreshold slope of 0.38 V/dec, and on/off ratio of 10<SUP>4</SUP>–10<SUP>5</SUP> were demonstrated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lanthanum-doped Al<SUB>2</SUB>O<SUB>3</SUB> gate dielectrics were fabricated by using a solution process. </LI> <LI> The lanthanum doping enhanced the dielectric properties of Al<SUB>2</SUB>O<SUB>3</SUB> films. </LI> <LI> Solution-processed indium-zinc-oxide thin-film transistors were demonstrated. </LI> </UL> </P>

Spin polarization and magneto-dielectric coupling in Al-modified thin iron oxide films -microwave mediated sol-gel approach

Sidra Khalid,Saira Riaz,Samia Naeem,Aseya Akbar,S. Sajjad Hussain,YB Xu,Shahzad Naseem 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-

Production of single-phase materials with multifunctional properties is still a challenge faced by materialscientists. In addition, obtaining high spin polarization efficiency in the materials that exhibit multifunctionalproperties is a big issue. A novel approach is suggested in this work for obtaining multifunctionalityand spin polarization in the same material. This approach has combined the effect of microwave radiationsand aluminum (Al) doping in iron oxide thin films during synthesis. Combined effect of microwaveradiations and Al doping results in controlling / tuning the structural transitions in iron oxide thin films. Pristine and 2–10 wt% Al doped iron oxide thin films are prepared and studied in detail. Raman analysisshows that 2 and 4 wt% Al concentration results in c-Fe2O3 + Fe3O4 phase with 71.3% and 64.5% of c-Fe2O3content, respectively. XRD and Raman analyses confirm the transition from c-Fe2O3 to Fe3O4 thin films atAl concentrations of 6–10 wt%. Structural transformation shows that microwave radiations catalyzes thatAl3+ions to occupy the vacancies on B sites of iron oxide thus, lead to the formation of Fe3O4. Observationof Verwey transition ~ 126 K also supports the transition in phases of iron oxide with increase in saturationmagnetization from 251.3emu/cm3 (pristine films) to 405.6emu/cm3 (8 wt% Al concentration). Highdielectric constant of ~ 135.5 (log f = 5.0) is observed for 8 wt% Al concentration. Conductivity anddetailed impedance & modulus analyses depict Mott’s hopping phenomenon along with presence of differentrelaxation times. Coupling between magnetic and dielectric properties is observed at room temperature. Magnetoresistance curves indicate spin polarization efficiency of ~24%.

Homojunction Solution-Processed Metal Oxide Thin-Film Transistors Using Passivation-Induced Channel Definition

Kim, Jung Hyun,Rim, You Seung,Kim, Hyun Jae American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.7

<P>A simple method of channel passivation and physical definition of solution-processed metal oxide thin-film transistors (TFTs) has been developed for aluminum oxide (AlO<SUB><I>x</I></SUB>) and indium oxide (InO<SUB><I>x</I></SUB>) thin films. A photoresist-free-based ultraviolet (UV) patterning process was used to define an InO<SUB><I>x</I></SUB> layer as the source/drain region and an AlO<SUB><I>x</I></SUB> layer as a passivation layer on the InO<SUB><I>x</I></SUB> layer. The Al diffused into the patterned InO<SUB><I>x</I></SUB> thin film during a thermal annealing step. As an electrode, the patterned InO<SUB><I>x</I></SUB> thin film had low resistivity, and as a channel, the Al-diffused InO<SUB><I>x</I></SUB> thin film had a low carrier concentration. Furthermore, the diffused Al behaved as a carrier suppressor by reducing oxygen vacancies within the InO<SUB><I>x</I></SUB> thin film. We succeeded in forming a coplanar homojunction-structured metal oxide TFT that used the passivation-induced channel-defining (PCD) method with an AlO<SUB><I>x</I></SUB>/InO<SUB><I>x</I></SUB> bilayer. The PCD TFT had a field-effect mobility of 0.02 cm<SUP>2</SUP>/V·s, a threshold voltage of −1.88 V, a subthreshold swing of 0.73 V/decade, and an on/off current ratio of 2.75 × 10<SUP>6</SUP> with a width/length (<I>W</I>/<I>L</I>) of 2000 μm/400 μm.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-7/am405712m/production/images/medium/am-2013-05712m_0006.gif'></P>

Properties of hafnium-aluminum-zinc-oxide thin films for the application of oxide-transistors

Lee, Sang-Hyuk,Jun, Hyun-Sik,Park, Ju-Hee,Kim, Won,Oh, Saeroonter,Park, Jin-Seok Elsevier 2016 THIN SOLID FILMS - Vol.620 No.-

<P><B>Abstract</B></P> <P>Hafnium-aluminum zinc oxide (HAZO) films as an active layer of oxide-transistors with different hafnium (Hf) contents were deposited via co-sputtering of separate targets. The effects of the sputtering power during co-sputtering on the structural, optical, electrical, and chemical properties of the HAZO films were examined. As the sputtering power increased, the structure of the HAZO films changed from polycrystalline to amorphous, and the HfO bonds in the HAZO films increased, but the ZnO bonds decreased. Also, a bottom-gate-type thin-film transistor (TFT) using the HAZO film as its channel layer was fabricated and characterized. The TFTs using HAZO layer at room temperature as channel layer exhibited the device characteristics, such as a field effect mobility of 0.45cm<SUP>2</SUP>/V·s, a threshold voltage of 17.18V, a subthreshold swing of 0.85V/decade, an on/off current ratio of 3.68×10<SUP>7</SUP>, and a visible transmittance of 82.7%. It was discovered that the changes of the electrical characteristics of the HAZO TFTs were closely related to the changes of the ZnO/HfO bonding ratio.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hafnium-aluminum-zinc-oxide (HAZO) films were deposited via co-sputtering. </LI> <LI> Hf content was controlled by varying the sputtering powers of Hf or HfO<SUB>2</SUB> targets. </LI> <LI> Chemical, structural, and optical properties of HAZO films were analyzed. </LI> <LI> The properties of HAZO films strongly depended on the Hf or HfO<SUB>2</SUB> sputtering power. </LI> <LI> Effects of Hf contents on the characteristics of HAZO-TFTs have been analyzed. </LI> </UL> </P>

Substrate-dependent Internal Stress of Aluminum-doped Zinc-oxide Thin Films Deposited by DC Magnetron Sputtering

김태원 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.4

The internal stress of very thin (30 nm) aluminum-doped zinc-oxide (AZO) films deposited by DC magnetron sputtering at room temperature was found to be strongly substrate dependent. The stress of an AZO film deposited on a single-crystalline Si wafer substrate changed more steeply than that of a film deposited on an amorphous glass substrate as deposition conditions, such as the sputter working pressure and the applied power on the cathode, were varied. This result can be explained by the atomistic peening effect which occurs more intensively in a more crystalline microstructure. Thus it can be inferred that the crystallinity of the substrate influences that of the growing film. In other words, the more crystalline the substrate is, the more crystalline the growing film is. Support for this point of view was supplied by the X-ray diffraction pattern result showing that the intensity of the (002) plane diffraction peak for the AZO film grown on a Si wafer was higher than that for an AZO film grown on glass. That is, the AZO film grown on a crystalline Si wafer is more crystalline than the AZO film grown on an amorphous glass wafer. This study confirmed that the substrate influenced the internal stress of the growing film strongly.

Investigation of atomic-layer-deposited Al-doped ZnO film for AZO/ZnO double-stacked active layer thin-film transistor application

Jeong, Jun-Kyo,Yun, Ho-Jin,Yang, Seung-Dong,Eom, Ki-Yun,Chea, Seong-Won,Park, Jeong-Hyun,Lee, Hi-Deok,Lee, Ga-Won Elsevier S.A. 2017 Thin Solid Films Vol.638 No.-

<P><B>Abstract</B></P> <P>In this study, Al-doped zinc oxide (AZO) thin films with different Al concentrations fabricated by atomic layer deposition are investigated to determine the Al doping effect for AZO/ZnO double-stacked active layer thin-film transistor (TFT) applications. The AZO films are analyzed by X-ray diffraction, photoluminescence, and X-ray photoelectron spectroscopy, which show that the Al dopants affect the crystallinity, including the crystal direction and grain size, and reduce the deep trap sites such as oxygen vacancies (V<SUB>O</SUB>). The optimized Al doping concentration is about 2%. TFTs with an AZO (2%)/ZnO double-stacked active layer are fabricated and shown to exhibit a lower threshold voltage (V<SUB>th</SUB>), subthreshold slope, and V<SUB>th</SUB> shift under a positive gate-bias stress compared to ZnO single-layer devices. In the case of the on-current, however, the AZO stacked devices exhibit a smaller value. These electrical characteristics can be explained by V<SUB>O</SUB> suppression and altered crystal properties due to Al doping. For the field-effect mobility, the temperature dependence also reveals that the main transport mechanisms are thermionic and thermal field emission over the grain boundary in the AZO stacked devices. These results indicate that the AZO film properties depend strongly on the Al concentration and hence the ZnO-based devices can be optimized for specific application by Al doping.</P> <P><B>Highlights</B></P> <P> <UL> <LI> AZO thin films with different Al doping concentration were analyzed. </LI> <LI> Through physical analysis, 2% AZO showed the best characteristics. </LI> <LI> The use of AZO showed improved stability through gate bias stress measurement. </LI> <LI> The main transport mechanism was analyzed through temperature dependence of mobility. </LI> <LI> The main transport mechanism is thermionic and thermal field emission. </LI> </UL> </P>