Pub Date : 2026-05-01Epub Date: 2026-01-06DOI: 10.1016/j.mssp.2025.110390
Tesalonika Siregar , Yunasfi , Mashadi , Wisnu Ari Adi , Budhy Kurniawan , Jan Setiawan
Phase purity and magnetic properties play a crucial role in determining the effectiveness of electromagnetic (EM) wave absorption. This study investigates the influence of milling duration and sintering temperature on the crystal structure, magnetic behavior, and microwave absorption performance of the perovskite material Co0.75Ni0.25Ti0.975Y0.025O3 (CNTYO), synthesized via the solid-state reaction assisted by high-energy milling. X-ray diffraction results confirmed the formation of a single-phase perovskite structure after ≥5 h of milling. The 7 h-milled sample exhibited the best absorption performance, with a minimum reflection loss (|RLmax|) of −21.94 dB at 6.17 GHz for a thickness of 1.5 mm. Prolonged milling enhanced microstructural homogeneity and interfacial polarization, improving impedance matching between the material and free space. Sintering at higher temperatures (1100–1200 °C) induced the formation of a Ti2Y2O7 secondary phase, which reduced defect density and magnetic dielectric losses, thereby weakening the overall absorption performance. The material exhibits low-magnetization magnetic behavior dominated by weak ferromagnetic or paramagnetic-like contributions. These findings emphasize that precise control of milling and sintering parameters is essential for tailoring phase purity, magnetic properties, and electromagnetic response, establishing CNTYO as a lightweight and thermally stable candidate for advanced radar-absorbing material (RAM) applications.
{"title":"Tuning phase purity, magnetic softness, and microwave absorption in Co0.75Ni0.25Ti0.975Y0.025O3 via controlled milling and sintering","authors":"Tesalonika Siregar , Yunasfi , Mashadi , Wisnu Ari Adi , Budhy Kurniawan , Jan Setiawan","doi":"10.1016/j.mssp.2025.110390","DOIUrl":"10.1016/j.mssp.2025.110390","url":null,"abstract":"<div><div>Phase purity and magnetic properties play a crucial role in determining the effectiveness of electromagnetic (EM) wave absorption. This study investigates the influence of milling duration and sintering temperature on the crystal structure, magnetic behavior, and microwave absorption performance of the perovskite material Co<sub>0</sub>.<sub>75</sub>Ni<sub>0</sub>.<sub>25</sub>Ti<sub>0</sub>.<sub>975</sub>Y<sub>0</sub>.<sub>025</sub>O<sub>3</sub> (CNTYO), synthesized via the solid-state reaction assisted by high-energy milling. X-ray diffraction results confirmed the formation of a single-phase perovskite structure after ≥5 h of milling. The 7 h-milled sample exhibited the best absorption performance, with a minimum reflection loss (|RL<sub>max</sub>|) of −21.94 dB at 6.17 GHz for a thickness of 1.5 mm. Prolonged milling enhanced microstructural homogeneity and interfacial polarization, improving impedance matching between the material and free space. Sintering at higher temperatures (1100–1200 °C) induced the formation of a Ti<sub>2</sub>Y<sub>2</sub>O<sub>7</sub> secondary phase, which reduced defect density and magnetic dielectric losses, thereby weakening the overall absorption performance. The material exhibits low-magnetization magnetic behavior dominated by weak ferromagnetic or paramagnetic-like contributions. These findings emphasize that precise control of milling and sintering parameters is essential for tailoring phase purity, magnetic properties, and electromagnetic response, establishing CNTYO as a lightweight and thermally stable candidate for advanced radar-absorbing material (RAM) applications.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110390"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-08DOI: 10.1016/j.mssp.2026.110410
Kai Du, Huafei Geng, Zhenjie Zhao, Xueyang Li, Gaojie Li
Developing high-performance hydrogen sensors is imperative for safe hydrogen utilization. PdPtMnCoNi high-entropy alloy (HEA) decorated Nb2O5 microspheres were synthesized via hydrothermal growth and liquid-phase reduction. Structural analyses confirmed uniform HEA nanoparticle dispersion (3–10 nm) on porous Nb2O5 microspheres, while XPS revealed enhanced surface oxygen adsorption and electron transfer at the HEA-Nb2O5 interface. The HEA/Nb2O5 sensor demonstrated exceptional hydrogen-sensing performance at 175 °C, achieving a rapid response time of 3 s–1000 ppm H2, a low detection limit (5 ppm), wide detection range (5–10000 ppm) and superior selectivity. The response of HEA/Nb2O5 sensor reached 28.5 % for 400 ppm H2, which is 35 times higher than that of the Nb2O5 (0.8 %). The introduction of HEA not only reduces the operating temperature of Nb2O5 sensor but also significantly enhances the response and selectivity to hydrogen. The improved sensing performance can be ascribed to the synergistic catalytic effects of HEA, which accelerate H2 dissociation and oxidation, and the formation of a Schottky barrier that modulates charge transport. This work highlights HEA decoration as a viable strategy for advancing oxide semiconductor-based gas sensors.
{"title":"PdPtMnCoNi high entropy alloy decorated Nb2O5 microspheres for rapid-response and high-selectivity hydrogen sensing","authors":"Kai Du, Huafei Geng, Zhenjie Zhao, Xueyang Li, Gaojie Li","doi":"10.1016/j.mssp.2026.110410","DOIUrl":"10.1016/j.mssp.2026.110410","url":null,"abstract":"<div><div>Developing high-performance hydrogen sensors is imperative for safe hydrogen utilization. PdPtMnCoNi high-entropy alloy (HEA) decorated Nb<sub>2</sub>O<sub>5</sub> microspheres were synthesized via hydrothermal growth and liquid-phase reduction. Structural analyses confirmed uniform HEA nanoparticle dispersion (3–10 nm) on porous Nb<sub>2</sub>O<sub>5</sub> microspheres, while XPS revealed enhanced surface oxygen adsorption and electron transfer at the HEA-Nb<sub>2</sub>O<sub>5</sub> interface. The HEA/Nb<sub>2</sub>O<sub>5</sub> sensor demonstrated exceptional hydrogen-sensing performance at 175 °C, achieving a rapid response time of 3 s–1000 ppm H<sub>2</sub>, a low detection limit (5 ppm), wide detection range (5–10000 ppm) and superior selectivity. The response of HEA/Nb<sub>2</sub>O<sub>5</sub> sensor reached 28.5 % for 400 ppm H<sub>2</sub>, which is 35 times higher than that of the Nb<sub>2</sub>O<sub>5</sub> (0.8 %). The introduction of HEA not only reduces the operating temperature of Nb<sub>2</sub>O<sub>5</sub> sensor but also significantly enhances the response and selectivity to hydrogen. The improved sensing performance can be ascribed to the synergistic catalytic effects of HEA, which accelerate H<sub>2</sub> dissociation and oxidation, and the formation of a Schottky barrier that modulates charge transport. This work highlights HEA decoration as a viable strategy for advancing oxide semiconductor-based gas sensors.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110410"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-19DOI: 10.1016/j.mssp.2026.110441
Tao Zhang , Chen Li , Han Han , Naihan Li , Eryang Wang , Guanghui Liu , Meng Wei , Song Xu , Jiehu Cui
WO3 has been proved as a superior semiconductor candidate showing great prospect for solar hydrogen production. Whereas, the fast charge recombination significantly limits the solar-to-hydrogen efficiency. Herein, we proposed a synergistic strategy of BiVO4 and CoOOH coatings on WO3 to boost charge transfer and photoelectrochemical (PEC) water splitting efficiency. Benefiting from the co-contributions of BiVO4 and CoOOH coatings, the constructed triple WO3/BiVO4/CoOOH composite photoanode achieved a water-oxidation photocurrent of 1.57 mA cm−2 at 1.23 V vs RHE, which is about 3.8 times than bare WO3 (0.41 mA cm−2). In addition, the incident photon-to-current conversion efficiency (IPCE) of composite photoanode enhanced 2.6 times at 420 nm compared with WO3. The synergistic role of BiVO4 and CoOOH coatings on charge dynamics and PEC efficiency of WO3 photoelectrode were intensive investigated by comprehensive characterizations of Mott-Schottky measurement (M − S), electrochemical impedance spectroscopy (EIS) and intensity-modulated photocurrent spectroscopy (IMPS), which revealed the improved charge density (Nd), reduced charge transfer resistance, suppressed charge carrier recombination (krec) and accelerated charge carrier transfer (ηtran) enable the boosted PEC performance of WO3 photoelectrode. The research provides a dual-modification strategy to construct a multilayer structured WO3-based photoanode for enhanced PEC performance.
WO3已被证明是一种优良的候选半导体材料,在太阳能制氢方面具有广阔的应用前景。然而,快速充电重组极大地限制了太阳能制氢的效率。在此,我们提出了BiVO4和CoOOH涂层在WO3上的协同策略,以提高电荷转移和光电化学(PEC)水分解效率。得益于BiVO4和CoOOH涂层的共同贡献,构建的三重WO3/BiVO4/CoOOH复合光阳极在1.23 V vs RHE下获得了1.57 mA cm−2的水氧化光电流,是裸WO3 (0.41 mA cm−2)的3.8倍。在420 nm处,复合光阳极的入射光子-电流转换效率(IPCE)比WO3提高了2.6倍。通过Mott-Schottky测量(M−S)、电化学阻抗谱(EIS)和强度调制光电流谱(IMPS)的综合表征,深入研究了BiVO4和CoOOH涂层对WO3光电极的电荷动力学和PEC效率的协同作用,发现BiVO4和CoOOH涂层提高了WO3光电极的电荷密度(Nd),降低了电荷转移电阻,抑制载流子复合(krec)和加速载流子转移(ηtran)可以提高WO3光电极的PEC性能。该研究提供了一种双改性策略来构建多层结构的wo3基光阳极,以提高PEC性能。
{"title":"Synergistic effects of BiVO4 and CoOOH coatings to accelerate charge transfer of WO3 photoanodes for improved photoelectrochemical water splitting","authors":"Tao Zhang , Chen Li , Han Han , Naihan Li , Eryang Wang , Guanghui Liu , Meng Wei , Song Xu , Jiehu Cui","doi":"10.1016/j.mssp.2026.110441","DOIUrl":"10.1016/j.mssp.2026.110441","url":null,"abstract":"<div><div>WO<sub>3</sub> has been proved as a superior semiconductor candidate showing great prospect for solar hydrogen production. Whereas, the fast charge recombination significantly limits the solar-to-hydrogen efficiency. Herein, we proposed a synergistic strategy of BiVO<sub>4</sub> and CoOOH coatings on WO<sub>3</sub> to boost charge transfer and photoelectrochemical (PEC) water splitting efficiency. Benefiting from the co-contributions of BiVO<sub>4</sub> and CoOOH coatings, the constructed triple WO<sub>3</sub>/BiVO<sub>4</sub>/CoOOH composite photoanode achieved a water-oxidation photocurrent of 1.57 mA cm<sup>−2</sup> at 1.23 V vs RHE, which is about 3.8 times than bare WO<sub>3</sub> (0.41 mA cm<sup>−2</sup>). In addition, the incident photon-to-current conversion efficiency (IPCE) of composite photoanode enhanced 2.6 times at 420 nm compared with WO<sub>3</sub>. The synergistic role of BiVO<sub>4</sub> and CoOOH coatings on charge dynamics and PEC efficiency of WO<sub>3</sub> photoelectrode were intensive investigated by comprehensive characterizations of Mott-Schottky measurement (M − S), electrochemical impedance spectroscopy (EIS) and intensity-modulated photocurrent spectroscopy (IMPS), which revealed the improved charge density (<em>N</em><sub>d</sub>), reduced charge transfer resistance, suppressed charge carrier recombination (<em>k</em><sub>rec</sub>) and accelerated charge carrier transfer (<em>η</em><sub>tran</sub>) enable the boosted PEC performance of WO<sub>3</sub> photoelectrode. The research provides a dual-modification strategy to construct a multilayer structured WO<sub>3</sub>-based photoanode for enhanced PEC performance.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110441"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-07DOI: 10.1016/j.mssp.2025.110402
Fedor Hrubišák , Milan Ťapajna , Fridrich Egyenes , Ondrej Pohorelec , Edmund Dobročka , Alica Rosová , Kristína Hušeková , Andrej Vincze , Pavol Noga , Tibor Izsák , Boris Hudec , Tomáš Ščepka , Filip Gucmann
Gallium oxide (Ga2O3) is a promising semiconductor material for high-power electronics; however, its low thermal conductivity is a challenge for the device performance and reliability. To address this issue, heteroepitaxial β-Ga2O3 thin films were grown on highly-thermally-conductive 4H-SiC substrates using liquid-injection MOCVD and subjected to H-containing annealing at different temperatures to enhance their conductivity. The MOSFET devices processed on Si-doped β-Ga2O3 films were annealed at identified optimal temperature of 550 °C, and showed output current of 0.8 mA/mm, ON/OFF current ratio of ∼106, and breakdown voltage of 150 V. Using structural, compositional, and electrical characterization of the films and devices, observed resistivity drop was attributed to H passivation of the compensating acceptor centers, possibly via formation of Ga-vacancy–hydrogen complexes. Low MOSFET output current was proposed to originate from nearest-neighbor hopping conduction with the activation energy of ∼141 meV. We propose the observed transport mechanism is a result of structural disorder introduced by O vacancies or Si-OH complexes. Further, another deeper donor with energy level of ∼69 meV was identified and assigned to Si atom occupying octahedrally-coordinated Ga site.
{"title":"The effect of hydrogen annealing on the electrical properties of β-Ga2O3/4H-SiC MOSFETs grown by liquid-injection MOCVD","authors":"Fedor Hrubišák , Milan Ťapajna , Fridrich Egyenes , Ondrej Pohorelec , Edmund Dobročka , Alica Rosová , Kristína Hušeková , Andrej Vincze , Pavol Noga , Tibor Izsák , Boris Hudec , Tomáš Ščepka , Filip Gucmann","doi":"10.1016/j.mssp.2025.110402","DOIUrl":"10.1016/j.mssp.2025.110402","url":null,"abstract":"<div><div>Gallium oxide (Ga<sub>2</sub>O<sub>3</sub>) is a promising semiconductor material for high-power electronics; however, its low thermal conductivity is a challenge for the device performance and reliability. To address this issue, heteroepitaxial β-Ga<sub>2</sub>O<sub>3</sub> thin films were grown on highly-thermally-conductive 4H-SiC substrates using liquid-injection MOCVD and subjected to H-containing annealing at different temperatures to enhance their conductivity. The MOSFET devices processed on Si-doped β-Ga<sub>2</sub>O<sub>3</sub> films were annealed at identified optimal temperature of 550 °C, and showed output current of 0.8 mA/mm, ON/OFF current ratio of ∼10<sup>6</sup>, and breakdown voltage of 150 V. Using structural, compositional, and electrical characterization of the films and devices, observed resistivity drop was attributed to H passivation of the compensating acceptor centers, possibly via formation of Ga-vacancy–hydrogen complexes. Low MOSFET output current was proposed to originate from nearest-neighbor hopping conduction with the activation energy of ∼141 meV. We propose the observed transport mechanism is a result of structural disorder introduced by O vacancies or Si-OH complexes. Further, another deeper donor with energy level of ∼69 meV was identified and assigned to Si atom occupying octahedrally-coordinated Ga site.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110402"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-06DOI: 10.1016/j.mssp.2026.110418
Junxiong Chai , Zhezhe Cong , Xiaoli Lu
Wide bandgap semiconductors have gained significant attention in RF device applications owing to their superior carrier mobility. To enhance the carrier mobility within the channel, researchers have employed the deposition of gate dielectrics to modulate the internal stress of GaN. Nevertheless, this dielectric deposition process inevitably introduces defects, which can detrimentally impact device performance. Our group previously demonstrated that the regulation of ferroelectric polarization effectively mitigates interface states. In this paper, the interplay between GaN internal stress and carrier mobility under the influence of nanochannel ferroelastic stress modulation has been explored. The output current and transconductance exhibited substantial enhancements, reaching 1026 mA/mm and 259 mS/mm, respectively. After the 680 nm channel formation, the compressive stress was reduced to 0.37 GPa, with carrier mobility increasing to 2610 cm2/V·s (110 % of the initial value). The reduction of compressive stress improves carrier mobility to a certain extent. This research provides a straightforward and efficacious approach to investigating the factors through which ferroelastic modulation influences the internal stress in GaN.
{"title":"Giant ferroelastic stress modulation in AlGaN/GaN heterostructure and its transport mechanism","authors":"Junxiong Chai , Zhezhe Cong , Xiaoli Lu","doi":"10.1016/j.mssp.2026.110418","DOIUrl":"10.1016/j.mssp.2026.110418","url":null,"abstract":"<div><div>Wide bandgap semiconductors have gained significant attention in RF device applications owing to their superior carrier mobility. To enhance the carrier mobility within the channel, researchers have employed the deposition of gate dielectrics to modulate the internal stress of GaN. Nevertheless, this dielectric deposition process inevitably introduces defects, which can detrimentally impact device performance. Our group previously demonstrated that the regulation of ferroelectric polarization effectively mitigates interface states. In this paper, the interplay between GaN internal stress and carrier mobility under the influence of nanochannel ferroelastic stress modulation has been explored. The output current and transconductance exhibited substantial enhancements, reaching 1026 mA/mm and 259 mS/mm, respectively. After the 680 nm channel formation, the compressive stress was reduced to 0.37 GPa, with carrier mobility increasing to 2610 cm<sup>2</sup>/V·s (110 % of the initial value). The reduction of compressive stress improves carrier mobility to a certain extent. This research provides a straightforward and efficacious approach to investigating the factors through which ferroelastic modulation influences the internal stress in GaN.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110418"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-05DOI: 10.1016/j.mssp.2025.110399
Fangzhou Wu , Yonglei Xing , Huijuan Liu , Xiaoyong Jin , Gang Ni
Peroxymonosulfate (PMS)–based advanced oxidation processes (AOPs) are promising for pollutant removal, whereas metal-doped carbons risk ion leaching. Here we report a metal-free selenium–nitrogen co-doped porous carbon (Se–N/C) that efficiently activates PMS for phenol (Ph) degradation. Selenium was chosen for its larger atomic radius and high polarizability, which modulate electronic structure and create active sites. Se–N/C achieved complete removal of parent Ph (Ph peak disappearance) within 10 min with a total organic carbon (TOC) reduction of 52 %, and a pseudo-first-order rate constant about twentyfold higher than nitrogen-doped carbon. Radical scavenging tests and electron paramagnetic resonance (EPR) confirm a dual pathway involving radical (O2•−) and non-radical (1O2) species. Density functional theory (DFT) indicates that co-doping tailors the electronic configuration, strengthens PMS adsorption (adsorption energy −3.07 eV), and enhances electron transfer. The catalyst remains active in the presence of common anions (SO42−, Cl−, NO3−, and H2PO4−) and humic acid, evidencing environmental tolerance. X-ray photoelectron spectroscopy and Raman spectroscopy identify graphitic nitrogen and C–Se–C as key centers, while selenium's antioxidative character supports cycling stability. This work provides a scalable, environmentally benign route for wastewater treatment and clarifies structure–activity relationships in PMS activation.
{"title":"Metal-free peroxymonosulfate activation for phenol degradation using selenium–nitrogen co-doped porous carbon nanosheets","authors":"Fangzhou Wu , Yonglei Xing , Huijuan Liu , Xiaoyong Jin , Gang Ni","doi":"10.1016/j.mssp.2025.110399","DOIUrl":"10.1016/j.mssp.2025.110399","url":null,"abstract":"<div><div>Peroxymonosulfate (PMS)–based advanced oxidation processes (AOPs) are promising for pollutant removal, whereas metal-doped carbons risk ion leaching. Here we report a metal-free selenium–nitrogen co-doped porous carbon (Se–N/C) that efficiently activates PMS for phenol (Ph) degradation. Selenium was chosen for its larger atomic radius and high polarizability, which modulate electronic structure and create active sites. Se–N/C achieved complete removal of parent Ph (Ph peak disappearance) within 10 min with a total organic carbon (TOC) reduction of 52 %, and a pseudo-first-order rate constant about twentyfold higher than nitrogen-doped carbon. Radical scavenging tests and electron paramagnetic resonance (EPR) confirm a dual pathway involving radical (O<sub>2</sub><sup>•−</sup>) and non-radical (<sup>1</sup>O<sub>2</sub>) species. Density functional theory (DFT) indicates that co-doping tailors the electronic configuration, strengthens PMS adsorption (adsorption energy −3.07 eV), and enhances electron transfer. The catalyst remains active in the presence of common anions (SO<sub>4</sub><sup>2−</sup>, Cl<sup>−</sup>, NO<sub>3</sub><sup>−</sup>, and H<sub>2</sub>PO<sub>4</sub><sup>−</sup>) and humic acid, evidencing environmental tolerance. X-ray photoelectron spectroscopy and Raman spectroscopy identify graphitic nitrogen and C–Se–C as key centers, while selenium's antioxidative character supports cycling stability. This work provides a scalable, environmentally benign route for wastewater treatment and clarifies structure–activity relationships in PMS activation.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110399"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-16DOI: 10.1016/j.mssp.2026.110428
N. Torabi , J.M. Delgado-Sanchez , E. Artegiani , J. Kuliček , B. Rezek , P. Jakuza , M. Meneghini , A. Romeo
This work investigates how the absorber thickness and a mild post-annealing treatment (PAT) in air jointly affect the structural and electrical properties of thermally evaporated Sb2Se3 absorbers, and the performance of superstrate solar cells. Sb2Se3 layers with thicknesses of 400, 800, and 1200 nm were deposited on a CdSe buffer and integrated in glass/SnO2:F/SnO2/CdSe/Sb2Se3/Au devices. Contrary to the usual expectation for thin-film absorbers, the thinnest device (400 nm) yields the highest power conversion efficiency (PCE), increasing from 2.8 % to 3.7 % after annealing in air, while thicker absorbers (800 and 1200 nm) only reach 3.5 % and 3.3 %, respectively. These trends correlate with a higher hole concentration (≈4.6 × 1016 cm−3 before PAT and ≈1.3 × 1017 cm−3 after PAT) and reduced defect density in the thinnest absorber, as revealed by CV/DLCP analysis, which also shows a narrowing of the space-charge region that favors carrier collection in ultra-thin devices.
Morphological and XRD analyses confirm conventional grain growth and only subtle changes in crystal orientation with thickness and annealing, indicating that microstructural evolution alone does not govern the efficiency trends. Instead, SIMS profiles show oxygen incorporation throughout the absorber after PAT, while PL measurements and the convergence of CV and DLCP profiles demonstrate suppression of deep defects. These observations point to oxygen-induced passivation of electrically active defects as the main mechanism behind the improved open-circuit voltage and fill factor. Overall, the results highlight that in Sb2Se3/CdSe solar cells with very high absorption coefficients, carrier transport, defect passivation, and space-charge region engineering are more critical than increasing the absorber thickness, enabling efficient devices with ultra-thin (400 nm) Sb2Se3 absorbers.
{"title":"How the absorber thickness affects the electrical and structural properties of Sb2Se3 solar cells","authors":"N. Torabi , J.M. Delgado-Sanchez , E. Artegiani , J. Kuliček , B. Rezek , P. Jakuza , M. Meneghini , A. Romeo","doi":"10.1016/j.mssp.2026.110428","DOIUrl":"10.1016/j.mssp.2026.110428","url":null,"abstract":"<div><div>This work investigates how the absorber thickness and a mild post-annealing treatment (PAT) in air jointly affect the structural and electrical properties of thermally evaporated Sb<sub>2</sub>Se<sub>3</sub> absorbers, and the performance of superstrate solar cells. Sb<sub>2</sub>Se<sub>3</sub> layers with thicknesses of 400, 800, and 1200 nm were deposited on a CdSe buffer and integrated in glass/SnO<sub>2</sub>:F/SnO<sub>2</sub>/CdSe/Sb<sub>2</sub>Se<sub>3</sub>/Au devices. Contrary to the usual expectation for thin-film absorbers, the thinnest device (400 nm) yields the highest power conversion efficiency (PCE), increasing from 2.8 % to 3.7 % after annealing in air, while thicker absorbers (800 and 1200 nm) only reach 3.5 % and 3.3 %, respectively. These trends correlate with a higher hole concentration (≈4.6 × 10<sup>16</sup> cm<sup>−3</sup> before PAT and ≈1.3 × 10<sup>17</sup> cm<sup>−3</sup> after PAT) and reduced defect density in the thinnest absorber, as revealed by CV/DLCP analysis, which also shows a narrowing of the space-charge region that favors carrier collection in ultra-thin devices.</div><div>Morphological and XRD analyses confirm conventional grain growth and only subtle changes in crystal orientation with thickness and annealing, indicating that microstructural evolution alone does not govern the efficiency trends. Instead, SIMS profiles show oxygen incorporation throughout the absorber after PAT, while PL measurements and the convergence of CV and DLCP profiles demonstrate suppression of deep defects. These observations point to oxygen-induced passivation of electrically active defects as the main mechanism behind the improved open-circuit voltage and fill factor. Overall, the results highlight that in Sb<sub>2</sub>Se<sub>3</sub>/CdSe solar cells with very high absorption coefficients, carrier transport, defect passivation, and space-charge region engineering are more critical than increasing the absorber thickness, enabling efficient devices with ultra-thin (400 nm) Sb<sub>2</sub>Se<sub>3</sub> absorbers.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110428"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-17DOI: 10.1016/j.mssp.2026.110435
Geetimallika Das, Bulumoni Kalita
This study explores the combined effects of co-doping and external strain on electronic and thermoelectric properties of LiCaB half-Heusler alloy using DFT method. Out of the two co-doped configurations, In-doped Li0.75Mg0.25CaB (In0.25Li0.50Mg0.25CaB) and Mg-doped Li0.75In0.25CaB (Mg0.25Li0.50In0.25CaB), the former is found to be more stable. It retains half-metallicity of its pristine state Li0.75Mg0.25CaB but exhibits modified electronic band structure with a reduced band gap and hence enhanced power factor (PF). Co-doping of heavier element such as In in Mg pre-doped LiCaB results in substantial reduction of lattice thermal conductivity (κl) caused by significant phonon-defect scattering. The reduced κl, supported by adequate PF, leads to notable increment of ∼87% in the total figure of merit (ZTtot) (0.73) at 800K compared to Li0.75Mg0.25CaB. There is further suppression in κl when In0.25Li0.50Mg0.25CaB alloy is subjected to -8% strain and accordingly, another ∼16% improvement in ZTtot (0.85) is obtained. In addition to this, the alloy displays notable thermoelectric response even at room temperature, as indicated by a tremendous jump in ZTtot from 0.40 to ∼0.71 under achievable tensile strain limit of 6%. Interestingly, the thermoelectric efficiency of In0.25Li0.50Mg0.25CaB is improved and remains consistent over a wide range of temperature under tensile strain conditions. The corresponding conversion efficiency (η) boosts up as compared to the unstrained alloy. These findings highlight the synergistic role of co-doping and strain for tuning thermoelectric properties of half-Heusler materials in ways desired for practical applications.
{"title":"Strain induced improvement and consistency in thermoelectric performance of Mg and In co-doped LiCaB half-Heusler alloy","authors":"Geetimallika Das, Bulumoni Kalita","doi":"10.1016/j.mssp.2026.110435","DOIUrl":"10.1016/j.mssp.2026.110435","url":null,"abstract":"<div><div>This study explores the combined effects of co-doping and external strain on electronic and thermoelectric properties of <em>LiCaB</em> half-Heusler alloy using DFT method. Out of the two co-doped configurations, <em>In</em>-doped <em>Li</em><sub><em>0.75</em></sub><em>Mg</em><sub><em>0.25</em></sub><em>CaB</em> (<em>In</em><sub><em>0.25</em></sub><em>Li</em><sub><em>0.50</em></sub><em>Mg</em><sub><em>0.25</em></sub><em>CaB</em>) and <em>Mg-</em>doped <em>Li</em><sub><em>0.75</em></sub><em>In</em><sub><em>0.25</em></sub><em>CaB</em> (<em>Mg</em><sub><em>0.25</em></sub><em>Li</em><sub><em>0.50</em></sub><em>In</em><sub><em>0.25</em></sub><em>CaB</em>), the former is found to be more stable. It retains half-metallicity of its pristine state <em>Li</em><sub><em>0.75</em></sub><em>Mg</em><sub><em>0.25</em></sub><em>CaB</em> but exhibits modified electronic band structure with a reduced band gap and hence enhanced power factor (<em>PF</em>). Co-doping of heavier element such as <em>In</em> in <em>Mg</em> pre-doped <em>LiCaB</em> results in substantial reduction of lattice thermal conductivity (<em>κ</em><sub><em>l</em></sub>) caused by significant phonon-defect scattering. The reduced <em>κ</em><sub><em>l</em></sub>, supported by adequate <em>PF</em>, leads to notable increment of ∼87% in the total figure of merit (<em>ZT</em><sub><em>tot</em></sub>) (0.73) at 800K compared to <em>Li</em><sub><em>0.75</em></sub><em>Mg</em><sub><em>0.25</em></sub><em>CaB</em>. There is further suppression in <em>κ</em><sub><em>l</em></sub> when <em>In</em><sub><em>0.25</em></sub><em>Li</em><sub><em>0.50</em></sub><em>Mg</em><sub><em>0.25</em></sub><em>CaB</em> alloy is subjected to -8% strain and accordingly, another ∼16% improvement in <em>ZT</em><sub><em>tot</em></sub> (0.85) is obtained. In addition to this, the alloy displays notable thermoelectric response even at room temperature, as indicated by a tremendous jump in <em>ZT</em><sub><em>tot</em></sub> from 0.40 to ∼0.71 under achievable tensile strain limit of 6%. Interestingly, the thermoelectric efficiency of <em>In</em><sub><em>0.25</em></sub><em>Li</em><sub><em>0.50</em></sub><em>Mg</em><sub><em>0.25</em></sub><em>CaB</em> is improved and remains consistent over a wide range of temperature under tensile strain conditions. The corresponding conversion efficiency (<em>η</em>) boosts up as compared to the unstrained alloy. These findings highlight the synergistic role of co-doping and strain for tuning thermoelectric properties of half-Heusler materials in ways desired for practical applications.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110435"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-21DOI: 10.1016/j.mssp.2026.110445
Qi-Zhong Ren , Ling-Hui Nie , Dong-Liang Li , Yan-Ping Jiang , Xiu-Juan Jiang , Xin-Gui Tang
A brain-like neural network constructed by memristors has attracted wide attention, which is expected to break the limitations of traditional von Neumann design. In the work, a flexible artificial synaptic device was prepared by radio-frequency magnetron sputtering, and the resistive switching characteristics were investigated. The transition between the high and low resistance states of this device is primarily attributed to the formation and fracture of conductive filaments. The device can achieve typical synaptic behaviors, including short-term/long-term plasticity, paired pulse facilitation and peak time-dependent plasticity. Importantly, the device still has stable synaptic properties under bending conditions. In addition, the convolutional neural network (CNN) constructed by the device has good accuracy for MNIST handwritten digit dataset and Fashion-MNIST clothing dataset. These results provide a feasible method for creating an effective neuromorphic network in the future.
{"title":"Flexible memristors based on ZrO2/ZnO heterojunctions for neuromorphic computing","authors":"Qi-Zhong Ren , Ling-Hui Nie , Dong-Liang Li , Yan-Ping Jiang , Xiu-Juan Jiang , Xin-Gui Tang","doi":"10.1016/j.mssp.2026.110445","DOIUrl":"10.1016/j.mssp.2026.110445","url":null,"abstract":"<div><div>A brain-like neural network constructed by memristors has attracted wide attention, which is expected to break the limitations of traditional von Neumann design. In the work, a flexible artificial synaptic device was prepared by radio-frequency magnetron sputtering, and the resistive switching characteristics were investigated. The transition between the high and low resistance states of this device is primarily attributed to the formation and fracture of conductive filaments. The device can achieve typical synaptic behaviors, including short-term/long-term plasticity, paired pulse facilitation and peak time-dependent plasticity. Importantly, the device still has stable synaptic properties under bending conditions. In addition, the convolutional neural network (CNN) constructed by the device has good accuracy for MNIST handwritten digit dataset and Fashion-MNIST clothing dataset. These results provide a feasible method for creating an effective neuromorphic network in the future.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"206 ","pages":"Article 110445"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}