Yunki Kim, Kyu-Jin Jo, Jin-Su Oh, Cheol-Woong Yang
{"title":"Bipolar Resistive Switching Characteristics of Ta/TaxMnyOz/Pt Structure for ReRAM Application with Large Resistance Window","authors":"Yunki Kim, Kyu-Jin Jo, Jin-Su Oh, Cheol-Woong Yang","doi":"10.1007/s13391-023-00440-5","DOIUrl":"10.1007/s13391-023-00440-5","url":null,"abstract":"<div><p>In this study, a resistive random-access memory device based on a Ta/Ta<sub>x</sub>Mn<sub>y</sub>O<sub>z</sub>/Pt metal–insulator–metal structure was fabricated and examined. The test device exhibited stable bipolar resistive switching characteristics with DC endurance of more than 300 cycles and robust retention up to 10<sup>4</sup> s at room temperature. Moreover, the device had a low forming voltage and a resistance window of ~ 10<sup>3</sup>. The conduction mechanism in each resistance state of the device was analyzed through current–voltage curve fitting. It was confirmed that the primary conduction mechanisms were ohmic and Poole–Frenkel conduction in the low- and high-resistance states, respectively. By analyzing the cross section of the fabricated device through transmission electron microscopy, it was found that the Ta<sub>x</sub>Mn<sub>y</sub>O<sub>z</sub> layer was deposited in amorphous form. The composition and chemical bonding state of the Ta<sub>x</sub>Mn<sub>y</sub>O<sub>z</sub> layer were also analyzed using X-ray photoelectron spectroscopy. With these characteristics, the amorphous Ta<sub>x</sub>Mn<sub>y</sub>O<sub>z</sub> layer has strong potential for nonvolatile memory applications.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 1","pages":"26 - 32"},"PeriodicalIF":2.1,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44636505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pyridine Vapor Annealing Induced Reversible Switching Emission and Enhanced Electroluminescent Performance of Poly(fluorene-co-dibenzothiophene-S,S-dioxide)","authors":"Junfei Liang, Tong Wu, Jun Chen","doi":"10.1007/s13391-023-00442-3","DOIUrl":"10.1007/s13391-023-00442-3","url":null,"abstract":"<div><p>In this article, we report on blue-green exciplex emission through pyridine solvent vapor annealing blue-light polymer PFSO10, which is comprised the strong electron-withdrawing dibenzo-thiophene-<i>S</i>,<i>S</i>-dioxide with the molar ratio of 10%. The photoluminescent spectrum of PFSO10 film emerged a fresh low-energy emission peaked at 482 nm after pyridine solvent vapor annealing, which was stemmed from the exciplex charge-transfer state between the PFSO10 and pyridine. It is worth noting that the exciplex emission peaked at 482 nm from the pyridine solvent vapor annealing film was disappeared after thermal annealed at 120 °C and its photoluminescent spectrum was similar to that of the pristine PFSO10 film. This similar phenomenon of photoluminescent spectrum was also occurred to the electroluminescent spectra of the PFSO10 films. Furthermore, the device performance of PFSO10 was achieved significant improvement after pyridine solvent vapor annealing. With optimizing the pyridine vapor annealing process, the device based on PFSO10 as emissive layer received a maximum luminous efficiency of 6.74 cd A<sup>−1</sup> with the peak brightness of 22,364 cd m<sup>−2</sup>, which was enlarged over 140% compared to that of 2.77 cd A<sup>−1</sup> for the pristine PFSO10. These results demonstrate that appropriate solvent vapor annealing can be a simple and effective strategy to realize the reversible switching emission and improve the device performance.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 2","pages":"183 - 191"},"PeriodicalIF":2.1,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44276533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dong Hyun Seo, Ju Won Kim, Jin-Hoo Seong, Hyo-Chang Lee, Sang-il Kim, TaeWan Kim
{"title":"Characteristics of Rhombohedral (3R) Structure of α-In2Se3 Nanosheets by Mechanical Exfoliation","authors":"Dong Hyun Seo, Ju Won Kim, Jin-Hoo Seong, Hyo-Chang Lee, Sang-il Kim, TaeWan Kim","doi":"10.1007/s13391-023-00439-y","DOIUrl":"10.1007/s13391-023-00439-y","url":null,"abstract":"<div><p>The mechanically exfoliated ultrathin 3R α-In<sub>2</sub>Se<sub>3</sub> nanosheets were transferred onto a SiO<sub>2</sub>/Si substrate. Using atomic force microscopy, it was confirmed that the transferred α-In<sub>2</sub>Se<sub>3</sub> transferred had a thickness of 15–120 nm. The thickness-dependence of Raman peaks of <span>({E}^{2})</span>, <span>({A}_{1}^{1})</span>, <span>({E}^{4})</span>, and <span>({A}_{1}^{2})</span> was observed from the Raman spectra. Moreover, the measured photoluminescence peak values in the range of 869–895 nm indicate a blue shift as the thickness decreases. The field-effect transistor based on α-In<sub>2</sub>Se<sub>3</sub> exhibited an n-type semiconductor behavior. From the transfer curve at gate voltage of 10 V, the derived values of the mobility and ON/OFF ratio are 24.26 cm<sup>2</sup> V<sup>− 1</sup> s<sup>− 1</sup> and 1.84, respectively. In addition, it was confirmed that the 3R α-In<sub>2</sub>Se<sub>3</sub> layers had a high photoresponsivity of up to approximately 34,500 A/W under illumination (<span>(lambda)</span> = 750 nm).</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 2","pages":"192 - 198"},"PeriodicalIF":2.1,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49408741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhanced Open-Circuit Voltage of Eco-Friendly Silver Bismuth Iodide Thin-Film Photovoltaics with PTB7 Polymer-Based Hole Transport Layer","authors":"Tae-Gyun Kwon, Taesu Kim, Younghoon Kim","doi":"10.1007/s13391-023-00437-0","DOIUrl":"10.1007/s13391-023-00437-0","url":null,"abstract":"<div><p>Next-generation and solution-processed thin-film solar cells have been attracted considerable attention because of their low cost, light weight, flexibility, and aesthetics. However, most of solution-processed thin-film solar cells are now focused on the use of photovoltaic absorbers containing the toxic element of Pb. In this study, eco-friendly silver-bismuth-iodide (Ag-Bi-I) thin-film photovoltaic devices with high open-circuit voltages (<i>V</i><sub>OC</sub>) are developed by utilizing polythieno[3,4-<i>b</i>]-thiophene-co-benzodithiophene (PTB7) as the hole transport layer (HTL). The solution-processed AgBi<sub>2</sub>I<sub>7</sub> semiconductor, which is an Ag-Bi-I ternary compound, exhibit features suitable for photovoltaic layers in thin-film solar cells, including a three-dimensional (3D) crystal structure, good surface morphology, and low optical bandgaps of 1.87 eV. Meanwhile, the solution-processed AgBi<sub>2</sub>I<sub>7</sub> thin-film solar cell based on the PTB7 HTL exhibit a power conversion efficiency of 0.94% with an improved <i>V</i><sub>OC</sub> value of 0.71 V owing to the deeper highest occupied molecular orbital (HOMO) energy level compared to that of poly(3-hexylthiophene-2,5-diyl) (P3HT). In other words, the <i>V</i><sub>OC</sub> of the PTB7 HTL-based device is 20% higher than that of the P3HT HTL-based control device. Our results provide a new approach for increasing the <i>V</i><sub>OC</sub> of eco-friendly Ag-Bi-I thin-film photovoltaics and indicate that further HTL engineering is necessary to simultaneously improve the <i>V</i><sub>OC</sub> and performance of the devices.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 2","pages":"165 - 172"},"PeriodicalIF":2.1,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46812768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. R. Khalid, Samavia Ilyas, Faisal Ali, Tahir Iqbal, M. Rafique, Muhammad Imran, Mohammad A. Assiri
{"title":"Novel Sn-Doped WO3 Photocatalyst to Degrade the Organic Pollutants Prepared by Green Synthesis Approach","authors":"N. R. Khalid, Samavia Ilyas, Faisal Ali, Tahir Iqbal, M. Rafique, Muhammad Imran, Mohammad A. Assiri","doi":"10.1007/s13391-023-00436-1","DOIUrl":"10.1007/s13391-023-00436-1","url":null,"abstract":"<div><p>The organic pollutants are polluting the drinking water so, it is a field of great interest to clean this water by using some sophisticated materials. For this purpose, the nanostructured materials are playing vital role to attain sustainable and pure drinking water by degrading organic pollutants. The synthesis of such photocatalytic material without using harmful chemicals, is one of the important existing challenges. Thus, to tackle this challenge, we have prepared green synthesized Sn-doped WO<sub>3</sub> nanomaterials by varying the content of Sn from 2 to 6 wt% and assisting from moringa oleifera seeds’ extract. The crystal structure, morphology, optical and photoluminescence properties of as prepared samples were investigated through x-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet visible spectroscopy (UV-vis) and photoluminescence spectroscopy (PL) techniques. Among of as prepared samples, the 4Sn-WO<sub>3</sub> (4 wt% Sn doped WO<sub>3</sub>) sample has exhibited the reduced optical band gap value i.e. 2.80 eV than 3.02 eV for pure WO<sub>3</sub> sample. This optimized sample has also shown the lowest e-h recombination rate. To test the photocatalytic performance, the methylene blue was used as a model dye. Out of all samples, 4Sn-WO<sub>3</sub> sample has shown 95% degradation activity against this water pollutant. These findings specify that the as mentioned novel photocatalytic nanomaterial will provide a significant advancement in the environmental field to degrade the organic pollutants.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 1","pages":"85 - 94"},"PeriodicalIF":2.1,"publicationDate":"2023-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43084297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Arief Mustajab, Pepen Arifin, Suprijadi Suprijadi, Toto Winata
{"title":"Enhanced Hall Mobility and d0 Ferromagnetism in Li-Doped ZnO Thin Films Prepared by Aerosol-Assisted CVD","authors":"Muhammad Arief Mustajab, Pepen Arifin, Suprijadi Suprijadi, Toto Winata","doi":"10.1007/s13391-023-00438-z","DOIUrl":"10.1007/s13391-023-00438-z","url":null,"abstract":"<div><p>Zinc oxide (ZnO) thin films with different concentrations of lithium, from 0 to 15 mol%, have been grown on Si(100) substrates by employing aerosol-assisted chemical vapor deposition (AACVD). The structural, electronic, and magnetic properties of the ZnO thin films were investigated as the effect of Li doping concentration. SEM images of surface morphology reveal that the undoped and low-concentration Li-doped ZnO thin films exhibit irregular ellipsoid grains. In comparison, the ZnO thin films with higher Li concentration consist of multi-aligned rod-like and hexagonal-shaped grains. XRD pattern analysis confirms that all grown ZnO thin films exhibit a single polycrystalline phase of hexagonal wurtzite crystal. The lattice reduction was observed in the Li-doped thin films indicating that the substitutional Li effectively occupied the Zn lattice site. The Hall effect measurement demonstrates that Li-doped ZnO films possess <i>p</i>-type conductivity. The resistivity of Li-doped ZnO thin films decreases with an increase in Li doping concentration while the hole carrier density increases. The Hall mobility tends to increase as more Li doping concentration is given, with the highest Hall mobility obtained from 15 mol% Li-doped film with a value of 85.88 cm<sup>2</sup>/V s. The VSM study demonstrates that all grown ZnO thin films exhibit an M-H hysteresis curve, indicating d<sup>0</sup> ferromagnetism behavior at room temperature, with coercivity ranging from 202 to 373 Oe. The highest saturation magnetization was obtained from 10 mol% Li-doped films, with a value of 5.55 × 10<sup>–2</sup> emu/g.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 2","pages":"111 - 121"},"PeriodicalIF":2.1,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42409368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of Electron Irradiation on Electronic Structure of Ni41Co6Mn43Sn10 Alloys","authors":"Sibo Sun, Jun Zhang, Zhiyong Gao, Wei Cai","doi":"10.1007/s13391-023-00432-5","DOIUrl":"10.1007/s13391-023-00432-5","url":null,"abstract":"<div><p>Effect of electron irradiation on electronic structure of Ni<sub>41</sub>Co<sub>6</sub>Mn<sub>43</sub>Sn<sub>10</sub> alloys were investigated by X-ray absorption fine structure, X-ray magnetic circular dichroism spectrometry and Mössbauer spectrometry. The local coordination environment of magnetic element significant changes after electron irradiation, the change in the peak intensity of the Co <i>L</i><sub>3</sub> edge is opposite to the Ni/Mn element, indicating that there is an electronic exchange between them. The crystal field symmetry is broken, the hyperfine field <i>H</i><sub>in</sub> of the Ni<sub>41</sub>Co<sub>6</sub>Mn<sub>43</sub>Sn<sub>10</sub> alloy increases from 8.80 to 9.06 T. Meanwhile, the spin magnetic moment of the Mn atom is significantly increased after electron irradiation.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>MCD, XAS spectra of Ni and Mn and Hyperfine field distribution of Ni<sub>41</sub>Co<sub>6</sub>Mn<sub>43</sub>Sn<sub>10</sub> alloys before and after electron irradiation</p></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 1","pages":"42 - 48"},"PeriodicalIF":2.1,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45359234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Woon Jae Ruh, Hyeon Jin Choi, Jong Hoon Kim, Seung Woo Jeon, Young-Kyun Noh, Mino Yang, Young Heon Kim
{"title":"Formation and Control of Hexagonal Pyramid Structures from GaN -Based Pillar-Shaped Structures Using Focused Ion-Beam Process","authors":"Woon Jae Ruh, Hyeon Jin Choi, Jong Hoon Kim, Seung Woo Jeon, Young-Kyun Noh, Mino Yang, Young Heon Kim","doi":"10.1007/s13391-023-00435-2","DOIUrl":"10.1007/s13391-023-00435-2","url":null,"abstract":"<p>The formation of controllable 3D structures on the surface of layered optoelectronic devices using GaN-based semiconductors is important for improving the external quantum efficiency by enhancing the light-emitting efficiency. In this study, as-grown short hexagonal pillar structures on GaN-based semiconductors were transformed into a hexagonal pyramid shape during a focused ion-beam process. After forming the hexagonal pyramid shape, it was found that the size of the hexagonal pyramid can be adjusted by varying the sputtering time while preserving the pyramid shape. The transformation of the as-grown pillar structures to 3D hexagonal pyramids was demonstrated by analyzing the morphological evolution with the sputtering time by simulating the FIB process and calculating the effective ion bombardment area during sputtering.</p>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 1","pages":"49 - 55"},"PeriodicalIF":2.1,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47461201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}