Karen M. Gambaryan, Owen Ernst, Torsten Boeck, Oliver Marquardt
We present a combined experimental and theoretical study of uncapped In(As, Sb, P) graded composition laterally coupled asymmetric double quantum dots (DQDs), suited for application in nanodiodes or single-photon nano-optical up- and downconverters in the mid-infrared spectral range. We provide details on the growth process using liquid-phase epitaxy and characterization using atomic-force microscopy and scanning electron microscopy (SEM). We find that most DQDs exhibit asymmetry such that the two quantum dots (QDs) of each pair have different dimensions, giving rise to correspondingly different quantum confinement of hole states localized in each QD. Based on these data, we have performed systematic simulations using an eight-band k·p model to identify the relationship between QD dimensions and the energy difference between corresponding confined hole states in the two QDs. Finally, we have determined the strength of an applied electric field required to energetically align the hole ground states of two QDs of different dimensions in order to facilitate hole tunneling to the next QD for further recombination and single-photon emission with a different wavelength.
{"title":"Energy level alignment of confined hole states in InAs1−x−ySbxPy asymmetric double quantum dots for single-photon energy up- and downconversion","authors":"Karen M. Gambaryan, Owen Ernst, Torsten Boeck, Oliver Marquardt","doi":"10.1063/5.0244778","DOIUrl":"https://doi.org/10.1063/5.0244778","url":null,"abstract":"We present a combined experimental and theoretical study of uncapped In(As, Sb, P) graded composition laterally coupled asymmetric double quantum dots (DQDs), suited for application in nanodiodes or single-photon nano-optical up- and downconverters in the mid-infrared spectral range. We provide details on the growth process using liquid-phase epitaxy and characterization using atomic-force microscopy and scanning electron microscopy (SEM). We find that most DQDs exhibit asymmetry such that the two quantum dots (QDs) of each pair have different dimensions, giving rise to correspondingly different quantum confinement of hole states localized in each QD. Based on these data, we have performed systematic simulations using an eight-band k·p model to identify the relationship between QD dimensions and the energy difference between corresponding confined hole states in the two QDs. Finally, we have determined the strength of an applied electric field required to energetically align the hole ground states of two QDs of different dimensions in order to facilitate hole tunneling to the next QD for further recombination and single-photon emission with a different wavelength.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"55 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiao Liu, Jicong Wang, Wenchao Tian, Yanrui Li, Jing Shi
Converting carbon dioxide into fuel and chemicals by utilizing solar energy represents a cutting-edge approach to carbon recovery and energy renewal. The transfer behavior of photogenerated electrons and built-in electric field of photocatalysts greatly affect the efficiency of the photoreduction reaction. Herein, the heterostructures composed of bismuth sodium titanate (BNT) ferroelectrics and silver nanoparticles (Ag NPs) are constructed to promote the photocatalytic CO2 performance. The large spontaneous polarization of BNT optimizes the transfer dynamics of photoinduced electrons and holes and causes energy band bending with strong intrinsic electric field. With the aid of Ag NPs, the BNT@xAg heterojunctions exhibit intensified light absorption due to the phenomenon of localized surface plasmon resonance (LSPR), which extends the visible light absorption spectrum and strengthens charge transfer. The modified catalysts demonstrate improved charge separation capacity and notably prolonged electron lifetime up to 40.95 ns. The synergistic effect of LSPR and intrinsic polarization significantly boosts the photocatalytic efficiency together with ultrahigh CO product selectivity, which is outstanding among the ferroelectric and other representative photocatalysts. This study elucidates the photocatalytic enhancement mechanism of plasmonic Ag decorated BNT and offers an alternative route for the design of efficient catalysts.
{"title":"Inductive effect of charge transfer in ferroelectrics and plasmonic Ag heterojunctions for enhanced CO2 photoreduction","authors":"Xiao Liu, Jicong Wang, Wenchao Tian, Yanrui Li, Jing Shi","doi":"10.1063/5.0254634","DOIUrl":"https://doi.org/10.1063/5.0254634","url":null,"abstract":"Converting carbon dioxide into fuel and chemicals by utilizing solar energy represents a cutting-edge approach to carbon recovery and energy renewal. The transfer behavior of photogenerated electrons and built-in electric field of photocatalysts greatly affect the efficiency of the photoreduction reaction. Herein, the heterostructures composed of bismuth sodium titanate (BNT) ferroelectrics and silver nanoparticles (Ag NPs) are constructed to promote the photocatalytic CO2 performance. The large spontaneous polarization of BNT optimizes the transfer dynamics of photoinduced electrons and holes and causes energy band bending with strong intrinsic electric field. With the aid of Ag NPs, the BNT@xAg heterojunctions exhibit intensified light absorption due to the phenomenon of localized surface plasmon resonance (LSPR), which extends the visible light absorption spectrum and strengthens charge transfer. The modified catalysts demonstrate improved charge separation capacity and notably prolonged electron lifetime up to 40.95 ns. The synergistic effect of LSPR and intrinsic polarization significantly boosts the photocatalytic efficiency together with ultrahigh CO product selectivity, which is outstanding among the ferroelectric and other representative photocatalysts. This study elucidates the photocatalytic enhancement mechanism of plasmonic Ag decorated BNT and offers an alternative route for the design of efficient catalysts.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"27 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Field-effect transistors (FETs) based on indium oxide (In2O3) nanofibers demonstrate significant potential for applications in next-generation electronic devices. However, In2O3 nanofiber FETs typically exhibit deteriorated electrical performance and bias stability due to the disordered arrangement of nanofibers and a high concentration of oxygen vacancy defects. In this study, In2O3 nanofibers were prepared by electrospinning, and the effects of nanofiber orientation and Y2O3 passivation on FET electrical performance were systematically investigated. The results indicate that after Y2O3 passivation, the aligned In2O3 nanofiber FETs exhibit enhanced electrical performance and superior positive bias stress and negative bias illumination stress stability. The Y2O3 passivation layer effectively prevents the penetration of external O2 and H2O molecules, while the diffusion of Y3+ into the back channel reduces oxygen vacancies, thereby improving device stability. When Al2O3 was employed as the dielectric layer, the electrical performance of aligned In2O3 nanofiber FET with Y2O3 passivation was further optimized, achieving a mobility of 18.2 cm2/V s and a subthreshold swing of 85 mV/dec. Meanwhile, the FET exhibits excellent environmental stability after 60 days of atmospheric exposure. This work provides a strategy for fabricating nanofiber-based FETs with high mobility and stability.
{"title":"Enhanced stability and mobility of aligned In2O3 nanofiber field-effect transistors with Y2O3 passivation","authors":"Likun Tian, Yao Dong, Guangtan Miao, Zezhong Yin, Guoxia Liu, Fukai Shan","doi":"10.1063/5.0252311","DOIUrl":"https://doi.org/10.1063/5.0252311","url":null,"abstract":"Field-effect transistors (FETs) based on indium oxide (In2O3) nanofibers demonstrate significant potential for applications in next-generation electronic devices. However, In2O3 nanofiber FETs typically exhibit deteriorated electrical performance and bias stability due to the disordered arrangement of nanofibers and a high concentration of oxygen vacancy defects. In this study, In2O3 nanofibers were prepared by electrospinning, and the effects of nanofiber orientation and Y2O3 passivation on FET electrical performance were systematically investigated. The results indicate that after Y2O3 passivation, the aligned In2O3 nanofiber FETs exhibit enhanced electrical performance and superior positive bias stress and negative bias illumination stress stability. The Y2O3 passivation layer effectively prevents the penetration of external O2 and H2O molecules, while the diffusion of Y3+ into the back channel reduces oxygen vacancies, thereby improving device stability. When Al2O3 was employed as the dielectric layer, the electrical performance of aligned In2O3 nanofiber FET with Y2O3 passivation was further optimized, achieving a mobility of 18.2 cm2/V s and a subthreshold swing of 85 mV/dec. Meanwhile, the FET exhibits excellent environmental stability after 60 days of atmospheric exposure. This work provides a strategy for fabricating nanofiber-based FETs with high mobility and stability.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"8 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hang Lei, Xincheng Zhou, Zhiheng Chen, Yongyin Liang, Daping Qiu, Xuelin Yang, Zilong Wang, Wenjie Mai
Zinc-ion batteries (ZIBs) are poised to play a pivotal role in the future energy storage market. However, the undesired growth of zinc dendrites and the prevalence of side reactions pose significant challenges that limit the practical application of ZIBs. The sophisticated structural design and crystal orientation of the Zn anode can effectively suppress the occurrence of zinc dendrites and side reactions. Herein, a highly oriented Zn (002) lattice plane on 3D conductive frameworks [Zn/TiN nanotubes (NTs)] is designed to address uncontrolled dendrite growth, water-induced side reactions, and suboptimal Zn metal utilization in ZIBs. By leveraging an abundance of active sites for Zn2+ adsorption, minimal charge transfer resistance, and the controlled growth of Zn crystal facets, the reversibility and stability of ZIBs can be significantly enhanced during the Zn plating/stripping process. Remarkably, fiber-ZIBs based on Zn/TiN NTs exhibit a large specific capacity, long-term cycling durability, and excellent mechanical properties. This work proposes an approach to achieve highly reversible zinc anodes from the perspective of nanostructure and crystal orientation.
{"title":"Construction of oriented Zn (002) facets via 3D conductive frameworks for enhanced performance in fiber-based zinc-ion batteries","authors":"Hang Lei, Xincheng Zhou, Zhiheng Chen, Yongyin Liang, Daping Qiu, Xuelin Yang, Zilong Wang, Wenjie Mai","doi":"10.1063/5.0252588","DOIUrl":"https://doi.org/10.1063/5.0252588","url":null,"abstract":"Zinc-ion batteries (ZIBs) are poised to play a pivotal role in the future energy storage market. However, the undesired growth of zinc dendrites and the prevalence of side reactions pose significant challenges that limit the practical application of ZIBs. The sophisticated structural design and crystal orientation of the Zn anode can effectively suppress the occurrence of zinc dendrites and side reactions. Herein, a highly oriented Zn (002) lattice plane on 3D conductive frameworks [Zn/TiN nanotubes (NTs)] is designed to address uncontrolled dendrite growth, water-induced side reactions, and suboptimal Zn metal utilization in ZIBs. By leveraging an abundance of active sites for Zn2+ adsorption, minimal charge transfer resistance, and the controlled growth of Zn crystal facets, the reversibility and stability of ZIBs can be significantly enhanced during the Zn plating/stripping process. Remarkably, fiber-ZIBs based on Zn/TiN NTs exhibit a large specific capacity, long-term cycling durability, and excellent mechanical properties. This work proposes an approach to achieve highly reversible zinc anodes from the perspective of nanostructure and crystal orientation.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"65 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Iung, L. Pérez Ramírez, A. Gloskovskii, C.-Yi Cho, M.-Y. Lao, S. De, T.-H Hou, C. Lubin, M. Gros-Jean, N. Barrett
In this paper, we address correlations between film thickness, phase composition, and oxygen vacancy (VO) distribution in scaled, hafnia-based ferroelectric capacitors (FeCAPs), necessary to achieve low operating voltages, higher endurance, and advanced node integration. Using x-ray photoelectron spectroscopy, hard x-ray photoelectron spectroscopy, grazing incidence x-ray diffraction, and electrical characterization, we investigate the evolution of phase composition and VO profiles in Hf0.5Zr0.5O2 (HZO) films of 6 and 10 nm thickness. We demonstrate that thinner films exhibit a greater fraction of the non-polar tetragonal phase (t-phase), with increased VO concentration at the interface, affecting the device performance. Electrical measurements reveal contrasting wake-up and fatigue behavior between the two thicknesses, with thinner films showing decreased remanent polarization (2PR) due to t-phase dominance and VO redistribution during field cycling. These findings highlight the critical interplay of strain, phase stability, and VO dynamics, providing key insights for the optimization of HZO-based FeCAPs for advanced, low-power memory applications.
{"title":"Oxygen vacancy distribution and phase composition in scaled, Hf0.5Zr0.5O2-based ferroelectric capacitors","authors":"T. Iung, L. Pérez Ramírez, A. Gloskovskii, C.-Yi Cho, M.-Y. Lao, S. De, T.-H Hou, C. Lubin, M. Gros-Jean, N. Barrett","doi":"10.1063/5.0245595","DOIUrl":"https://doi.org/10.1063/5.0245595","url":null,"abstract":"In this paper, we address correlations between film thickness, phase composition, and oxygen vacancy (VO) distribution in scaled, hafnia-based ferroelectric capacitors (FeCAPs), necessary to achieve low operating voltages, higher endurance, and advanced node integration. Using x-ray photoelectron spectroscopy, hard x-ray photoelectron spectroscopy, grazing incidence x-ray diffraction, and electrical characterization, we investigate the evolution of phase composition and VO profiles in Hf0.5Zr0.5O2 (HZO) films of 6 and 10 nm thickness. We demonstrate that thinner films exhibit a greater fraction of the non-polar tetragonal phase (t-phase), with increased VO concentration at the interface, affecting the device performance. Electrical measurements reveal contrasting wake-up and fatigue behavior between the two thicknesses, with thinner films showing decreased remanent polarization (2PR) due to t-phase dominance and VO redistribution during field cycling. These findings highlight the critical interplay of strain, phase stability, and VO dynamics, providing key insights for the optimization of HZO-based FeCAPs for advanced, low-power memory applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"19 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kornelius Tetzner, Andreas Thies, Enrico Brusaterra, Alexander Külberg, Pallabi Paul, Ina Ostermay, Joachim Würfl, Oliver Hilt
In this work, we report on the fabrication of all-implanted β-Ga2O3 metal-oxide-semiconductor field-effect transistor (MOSFET) devices on semi-insulating (-201) β-Ga2O3 substrates. Through the use of multiple energy Si+ implantation and subsequent annealing, we were able to achieve high activation efficiencies up to 87% allowing to realize the active transistor channel and Ohmic contact regions with electrical properties comparable to homoepitaxial layers grown by metal-organic chemical vapor deposition. The fabricated β-Ga2O3 MOSFET devices featured excellent current modulation with on/off current ratios up to 109, maximum drain current densities of 180 mA/mm, and specific on-resistances of 1.5 mΩcm2. Furthermore, breakdown measurements in air of the non-field-plated MOSFET devices with a gate-to-drain distance of 2 μm showed a catastrophic breakdown at 332 V, which equals an average breakdown strength of 1.7 MV/cm. The outcome of this work emphasizes the high potential of this all-implantation approach for fabricating high-performing Ga2O3-based electronic devices for next-generation power electronics applications without the need of sophisticated high-quality epitaxial growth.
{"title":"All-implanted lateral β-Ga2O3 MOSFET devices realized on semi-insulating (-201) β-Ga2O3 substrates","authors":"Kornelius Tetzner, Andreas Thies, Enrico Brusaterra, Alexander Külberg, Pallabi Paul, Ina Ostermay, Joachim Würfl, Oliver Hilt","doi":"10.1063/5.0253992","DOIUrl":"https://doi.org/10.1063/5.0253992","url":null,"abstract":"In this work, we report on the fabrication of all-implanted β-Ga2O3 metal-oxide-semiconductor field-effect transistor (MOSFET) devices on semi-insulating (-201) β-Ga2O3 substrates. Through the use of multiple energy Si+ implantation and subsequent annealing, we were able to achieve high activation efficiencies up to 87% allowing to realize the active transistor channel and Ohmic contact regions with electrical properties comparable to homoepitaxial layers grown by metal-organic chemical vapor deposition. The fabricated β-Ga2O3 MOSFET devices featured excellent current modulation with on/off current ratios up to 109, maximum drain current densities of 180 mA/mm, and specific on-resistances of 1.5 mΩcm2. Furthermore, breakdown measurements in air of the non-field-plated MOSFET devices with a gate-to-drain distance of 2 μm showed a catastrophic breakdown at 332 V, which equals an average breakdown strength of 1.7 MV/cm. The outcome of this work emphasizes the high potential of this all-implantation approach for fabricating high-performing Ga2O3-based electronic devices for next-generation power electronics applications without the need of sophisticated high-quality epitaxial growth.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"78 5 Pt 1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongseung Lee, Jaewook Yoo, Hyeonjun Song, Binhyeong Lee, Soon Joo Yoon, Seongbin Lim, Jo Hak Jeong, Soyeon Kim, Minah Park, Seohyeon Park, Sojin Jung, Bhishma Pandit, Taehwan Moon, Jin-Ha Hwang, Kiyoung Lee, Yoon Kyeung Lee, Keun Heo, Hagyoul Bae
This work reports the impact of gamma-ray (γ-ray) irradiation-induced degradation based on the trap behaviors in amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. By employing multiple measurement configurations via low-frequency noise and direct current I–V characterization, we quantitatively investigated the energetic distribution of subgap density-of-states in the a-IGZO channel and the spatial distribution of oxide traps (Not) in the gate insulator, respectively. Also, the qualitative analysis was performed to determine the oxygen-related defects after γ-ray irradiation using x-ray photoelectron spectroscopy. Furthermore, the validity of our results was additionally confirmed by measuring the breakdown voltage and applying positive-bias stress to the fabricated devices exposed to radiation for accelerated tests.
{"title":"Low-frequency noise and DC I–V characterization of gamma-ray irradiation-induced degradation and trap behaviors in a-IGZO TFTs","authors":"Hongseung Lee, Jaewook Yoo, Hyeonjun Song, Binhyeong Lee, Soon Joo Yoon, Seongbin Lim, Jo Hak Jeong, Soyeon Kim, Minah Park, Seohyeon Park, Sojin Jung, Bhishma Pandit, Taehwan Moon, Jin-Ha Hwang, Kiyoung Lee, Yoon Kyeung Lee, Keun Heo, Hagyoul Bae","doi":"10.1063/5.0238211","DOIUrl":"https://doi.org/10.1063/5.0238211","url":null,"abstract":"This work reports the impact of gamma-ray (γ-ray) irradiation-induced degradation based on the trap behaviors in amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. By employing multiple measurement configurations via low-frequency noise and direct current I–V characterization, we quantitatively investigated the energetic distribution of subgap density-of-states in the a-IGZO channel and the spatial distribution of oxide traps (Not) in the gate insulator, respectively. Also, the qualitative analysis was performed to determine the oxygen-related defects after γ-ray irradiation using x-ray photoelectron spectroscopy. Furthermore, the validity of our results was additionally confirmed by measuring the breakdown voltage and applying positive-bias stress to the fabricated devices exposed to radiation for accelerated tests.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"63 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alternating current poling (ACP) and light fields have been studied as domain engineering methods for regulating the domain structures and improving the physical properties of ferroelectric crystals because of their convenience, effectiveness, and economic advantages. In this study, we propose a LACP method (ACP under above-bandgap light illumination), by which the transparency and electro-optic properties of Mn- and Fe-doped KTa1−xNbxO3 single crystals were improved compared with only ACP. Furthermore, the mechanical quality factor (Qm = 538) of the sample poled using the LACP method increased significantly by 206% in contrast to that of the sample poled by the conventional high-temperature direct current poling method. The results reveal that the light-induced reorientation of defect dipoles is responsible for the enhancement of the ACP quality and Qm. This study provides an efficient and fast poling approach to the material design for multifunctional devices.
{"title":"Light-induced enhancement of alternating current poling quality and mechanical quality factor in ferroelectric single crystals","authors":"Xinyu Jin, Yu Wang, Xiangda Meng, Bohan Xing, Xing Wen, Jinyu Ruan, Xiaoou Wang, Chengpeng Hu, Peng Tan, Hao Tian","doi":"10.1063/5.0251350","DOIUrl":"https://doi.org/10.1063/5.0251350","url":null,"abstract":"Alternating current poling (ACP) and light fields have been studied as domain engineering methods for regulating the domain structures and improving the physical properties of ferroelectric crystals because of their convenience, effectiveness, and economic advantages. In this study, we propose a LACP method (ACP under above-bandgap light illumination), by which the transparency and electro-optic properties of Mn- and Fe-doped KTa1−xNbxO3 single crystals were improved compared with only ACP. Furthermore, the mechanical quality factor (Qm = 538) of the sample poled using the LACP method increased significantly by 206% in contrast to that of the sample poled by the conventional high-temperature direct current poling method. The results reveal that the light-induced reorientation of defect dipoles is responsible for the enhancement of the ACP quality and Qm. This study provides an efficient and fast poling approach to the material design for multifunctional devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"21 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thijs Janssen, Lodewijk J. P. Vossen, Marcel A. Verheijen, Wilhelmus M. M. Kessels, Adriaan J. M. Mackus
To meet the demands for more advanced computer chips, creating devices with advanced 3D architectures is becoming commonplace in the semiconductor industry. To ensure alignment between the different layers, the bottom-up technique of area-selective deposition (ASD) is promising. However, ASD may not always be feasible depending on the various surface chemistries present during manufacturing of complex semiconductor devices. Topographically selective deposition (TSD) is emerging as an alternative, focusing on differences in surface orientation rather than chemical properties. This work demonstrates a TSD supercycle approach in which atomic layer deposition (ALD) is directed to proceed exclusively within a 3D trench structure, by covering the top of the trench with an amorphous carbon (aC) inhibition layer. The aC layer is applied selectively on the top surface of the trench by exploiting the ion-radical synergy required for its deposition. Since the aC layer lacks adsorption sites for ALD precursors, growth of the target material is inhibited on the top surface of the trench, whereas it occurs selectively within the trench. After several ALD cycles of selective deposition of the target material, the aC layer is removed and reapplied in a supercycle recipe until sufficient material has been deposited in the trench. The selective deposition of an aC inhibition layer on the top surface of the trench, as well as the selective deposition of 3.0 ± 0.1 nm of TiO2 in a trench is demonstrated on a 3D nanostructure.
{"title":"Topographically selective atomic layer deposition within trenches enabled by an amorphous carbon inhibition layer","authors":"Thijs Janssen, Lodewijk J. P. Vossen, Marcel A. Verheijen, Wilhelmus M. M. Kessels, Adriaan J. M. Mackus","doi":"10.1063/5.0246311","DOIUrl":"https://doi.org/10.1063/5.0246311","url":null,"abstract":"To meet the demands for more advanced computer chips, creating devices with advanced 3D architectures is becoming commonplace in the semiconductor industry. To ensure alignment between the different layers, the bottom-up technique of area-selective deposition (ASD) is promising. However, ASD may not always be feasible depending on the various surface chemistries present during manufacturing of complex semiconductor devices. Topographically selective deposition (TSD) is emerging as an alternative, focusing on differences in surface orientation rather than chemical properties. This work demonstrates a TSD supercycle approach in which atomic layer deposition (ALD) is directed to proceed exclusively within a 3D trench structure, by covering the top of the trench with an amorphous carbon (aC) inhibition layer. The aC layer is applied selectively on the top surface of the trench by exploiting the ion-radical synergy required for its deposition. Since the aC layer lacks adsorption sites for ALD precursors, growth of the target material is inhibited on the top surface of the trench, whereas it occurs selectively within the trench. After several ALD cycles of selective deposition of the target material, the aC layer is removed and reapplied in a supercycle recipe until sufficient material has been deposited in the trench. The selective deposition of an aC inhibition layer on the top surface of the trench, as well as the selective deposition of 3.0 ± 0.1 nm of TiO2 in a trench is demonstrated on a 3D nanostructure.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"99 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qimin Yan, John L. Lyons, Luke Gordon, Anderson Janotti, Chris G. Van de Walle
Oxygen is a common impurity in AlN samples. Using hybrid density functional calculations, we investigate the role of substitutional oxygen (ON) in the optical absorption. We construct configuration coordination diagrams for ON and related complexes. Our results indicate that an optical transition involving ON− (a DX center) gives rise to an absorption band peaked at 2.22 eV, suggesting it is a source of the absorption band with an onset at ∼ 2 eV observed in oxygen-containing samples. We also propose that neutral ON–DX complexes can form, which would give rise to absorption peaking at 3.06 eV. In addition, we find that oxygen, in spite of its DX character, may behave as an “optically shallow donor” and be involved in optical transitions from deep defect states to the conduction band. This observation provides an alternative physical mechanism for the optical absorption bands observed in AlN samples in the visible and ultraviolet (UV) region.
{"title":"Oxygen impurities in AlN and their impact on optical absorption","authors":"Qimin Yan, John L. Lyons, Luke Gordon, Anderson Janotti, Chris G. Van de Walle","doi":"10.1063/5.0234655","DOIUrl":"https://doi.org/10.1063/5.0234655","url":null,"abstract":"Oxygen is a common impurity in AlN samples. Using hybrid density functional calculations, we investigate the role of substitutional oxygen (ON) in the optical absorption. We construct configuration coordination diagrams for ON and related complexes. Our results indicate that an optical transition involving ON− (a DX center) gives rise to an absorption band peaked at 2.22 eV, suggesting it is a source of the absorption band with an onset at ∼ 2 eV observed in oxygen-containing samples. We also propose that neutral ON–DX complexes can form, which would give rise to absorption peaking at 3.06 eV. In addition, we find that oxygen, in spite of its DX character, may behave as an “optically shallow donor” and be involved in optical transitions from deep defect states to the conduction band. This observation provides an alternative physical mechanism for the optical absorption bands observed in AlN samples in the visible and ultraviolet (UV) region.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"12 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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