Applied Physics Letters最新文献_第2页

Versatile hybrid optical waveguides in amorphous silicon carbide with enhanced functionality and performance 功能和性能更强的非晶碳化硅多功能混合光波导

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-11 DOI: 10.1063/5.0222085

Mohammad Talebi Khoshmehr, Mahdi Mozdoor Dashtabi, Hamed Nikbakht, Bruno Lopez Rodriguez, Naresh Sharma, Iman Esmaeil Zadeh, Bob van Someren, B. Imran Akca

{"title":"Versatile hybrid optical waveguides in amorphous silicon carbide with enhanced functionality and performance","authors":"Mohammad Talebi Khoshmehr, Mahdi Mozdoor Dashtabi, Hamed Nikbakht, Bruno Lopez Rodriguez, Naresh Sharma, Iman Esmaeil Zadeh, Bob van Someren, B. Imran Akca","doi":"10.1063/5.0222085","DOIUrl":"https://doi.org/10.1063/5.0222085","url":null,"abstract":"In most optical waveguides employed within photonic integrated circuits, light confinement is achieved by etching the high-index layer. However, these waveguides often lack versatility in optimizing optical properties, such as mode size, shape, dispersion, and polarization. Moreover, they frequently suffer from high coupling losses and their propagation losses are significantly influenced by the quality of the etching process, especially for materials with high mechanical rigidity. Here, we present a hybrid optical waveguide concept that effectively addresses these limitations by combining a strip of easily processible low-index material (SU8) with a high-index hard-to-etch guiding layer (amorphous silicon carbide, SiC). Our approach not only eliminates the need for SiC etching but also offers flexibility in waveguide design to accommodate advanced functionalities. One of the key advancements of this hybrid configuration is its ability to suppress the transverse magnetic mode by 62 dB at 1550 nm, effectively functioning as a transverse electric pass waveguide. This simplifies the measurements by eliminating the need for polarization controllers and polarizers. Furthermore, through tailored waveguides, we achieve 2.5 times higher coupling efficiency compared to untapered hybrid SiC waveguides. We also demonstrate that thermal baking of the polymer layer reduces the scattering losses from 1.57 to 1.3 dB/cm. In essence, our hybrid approach offers a versatile way of realizing low-loss SiC-based integrated optical components with advanced features, such as excellent polarization suppression, flexible mode shapes, and dispersion control, compared to etched counterparts.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142171369","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}

引用次数: 0

Magnetic relaxometry of methemoglobin by widefield nitrogen-vacancy microscopy 通过宽场氮空位显微镜测量高铁血红蛋白的磁弛度

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-11 DOI: 10.1063/5.0217987

Suvechhya Lamichhane, Evelyn Carreto Guevara, Ilja Fescenko, Sy-Hwang Liou, Rebecca Y. Lai, Abdelghani Laraoui

{"title":"Magnetic relaxometry of methemoglobin by widefield nitrogen-vacancy microscopy","authors":"Suvechhya Lamichhane, Evelyn Carreto Guevara, Ilja Fescenko, Sy-Hwang Liou, Rebecca Y. Lai, Abdelghani Laraoui","doi":"10.1063/5.0217987","DOIUrl":"https://doi.org/10.1063/5.0217987","url":null,"abstract":"Hemoglobin (Hb) is a multifaceted protein, classified as a metalloprotein, chromoprotein, and globulin. It incorporates iron, which plays a crucial role in transporting oxygen within red blood cells. Hb functions by carrying oxygen from the respiratory organs to diverse tissues in the body, where it releases oxygen to fuel aerobic respiration, thus supporting the organism's metabolic processes. Hb can exist in several forms, primarily distinguished by the oxidation state of the iron in the heme group, including methemoglobin (MetHb). Measuring the concentration of MetHb is crucial because it cannot transport oxygen; hence, higher concentrations of MetHb in the blood causes methemoglobinemia. Here, we use optically detected magnetic relaxometry of paramagnetic iron spins in MetHb drop-cast onto a nanostructured diamond doped with shallow high-density nitrogen-vacancy (NV) spin qubits. We vary the concentration of MetHb in the range of 6 × 106–1.8 × 107 adsorbed Fe+3 spins per micrometer squared and observe an increase in the NV relaxation rate Γ1 (=1/T1, where T1 is the NV spin lattice relaxation time) up to 2 × 103 s−1. NV magnetic relaxometry of MetHb in phosphate-buffered saline solution shows a similar effect with an increase in Γ1 to 6.7 × 103 s−1 upon increasing the MetHb concentration to 100 μM. The increase in NV Γ1 is explained by the increased spin noise coming from the Fe+3 spins present in MetHb proteins. This study presents an additional usage of NV quantum sensors to detect paramagnetic centers of biomolecules at volumes below 100 picoliter.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142171374","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}

引用次数: 0

Crack-free > 1-μm AlN layer on Si substrate using ductile interlayer for strain modification in epitaxial film 利用延展性中间膜在硅衬底上形成无裂纹 > 1-μm AlN 层，实现外延薄膜的应变改性

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-11 DOI: 10.1063/5.0219833

Muhammad Aqib, Mina Moradnia, Mihee Ji, Vijay S. Parameshwaran, Wendy L. Sarney, Sara Pouladi, Nam-In Kim, Rheno Paul Rajesh Kumar, Gregory A. Garrett, Anand V. Sampath, Rebecca L. Forrest, Jae-Hyun Ryou

{"title":"Crack-free > 1-μm AlN layer on Si substrate using ductile interlayer for strain modification in epitaxial film","authors":"Muhammad Aqib, Mina Moradnia, Mihee Ji, Vijay S. Parameshwaran, Wendy L. Sarney, Sara Pouladi, Nam-In Kim, Rheno Paul Rajesh Kumar, Gregory A. Garrett, Anand V. Sampath, Rebecca L. Forrest, Jae-Hyun Ryou","doi":"10.1063/5.0219833","DOIUrl":"https://doi.org/10.1063/5.0219833","url":null,"abstract":"Growing crack-free, epitaxial ultrawide-bandgap semiconductor films on cost-effective, large-area substrates, such as AlN on Si, poses a significant challenge due to substantial lattice and thermal expansion mismatches. We introduce an approach to mitigate tensile strain or reverse strain signs between the substrate and the AlN layer, thereby suppressing crack formation during the heteroepitaxial growth of thick III-N films. This approach introduces ductile metallic interlayers, specifically Au, to change the strain state of AlN from in-plane tensile to compressive, without initiating cracks. Furthermore, the Au interlayer is grown epitaxially as a single crystal, which prevents the transfer of tensile strain into the AlN film, as confirmed by x-ray diffraction and transmission electron microscopy. We demonstrate crack-free AlN films exceeding 1 μm in thickness. These findings hold significant promise for advancing the field of ultrawide-bandgap semiconductor materials, with potential applications in electronic, optoelectronic, sensing, and energy device applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142171410","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}

引用次数: 0

Macrospin study on magnetization reversal in synthetic antiferromagnetically coupled composite of perpendicularly magnetized nanomagnets 垂直磁化纳米磁体合成反铁磁耦合复合体中磁化反转的宏旋研究

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-11 DOI: 10.1063/5.0224121

Toshiki Yamaji, Hiroshi Imamura

引用次数: 0

Nonequilibrium bandgap modification in porphyrin-based metal-organic frameworks revealed by transient absorption spectroscopy 瞬态吸收光谱揭示卟啉基金属有机框架的非平衡带隙改性

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-10 DOI: 10.1063/5.0218768

Yadong Han, Junhong Yu, Yunfan Yang, Hang Zhang, Zhengbang Wang, Jianbo Hu

{"title":"Nonequilibrium bandgap modification in porphyrin-based metal-organic frameworks revealed by transient absorption spectroscopy","authors":"Yadong Han, Junhong Yu, Yunfan Yang, Hang Zhang, Zhengbang Wang, Jianbo Hu","doi":"10.1063/5.0218768","DOIUrl":"https://doi.org/10.1063/5.0218768","url":null,"abstract":"Modifying the equilibrium bandgap has proven to be an effective strategy for optimizing photocarrier properties in metal-organic frameworks (MOFs). In this work, we have investigated the nonequilibrium bandgap modification in cobalt porphyrin-based MOF (Co-TCPP MOF) nanofilms through transient absorption spectroscopy. Our results reveal a captivating redshift–blueshift crossover in the nonequilibrium bandgap of Co-TCPP MOFs, with a staggering maximum shifting value of approximately 170 meV, achieved with an excitation fluence of 96 μJ/cm2. This phenomenon sets the stage for further investigations into harnessing nonequilibrium bandgap modification as a powerful tool for tailoring photocarrier properties. Another key facet of our research is the revelation that the bandgap modification effect observed in Co-TCPP MOFs is strongly dependent on the excitation fluence and is absent in disordered porphyrin molecules. This observation suggests a correlation between the bandgap modification and the amplified many-body interactions present within the ordered MOF structure, thus offering valuable insights into the intricate relationship between bandgap modification, excitation fluence, and ordered MOF structures.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166390","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}

引用次数: 0

Destructive dielectric breakdown of 2D muscovite mica 二维云母的破坏性介电击穿

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-10 DOI: 10.1063/5.0222048

A. Maruvada, S. J. O'Shea, J. Deng, K. Shubhakar, N. Raghavan, K. L. Pey

{"title":"Destructive dielectric breakdown of 2D muscovite mica","authors":"A. Maruvada, S. J. O'Shea, J. Deng, K. Shubhakar, N. Raghavan, K. L. Pey","doi":"10.1063/5.0222048","DOIUrl":"https://doi.org/10.1063/5.0222048","url":null,"abstract":"This study investigates the destructive breakdown (DBD) phenomenon in the van der Waals gate dielectric 2D muscovite mica (4–12 nm thick), focusing on its electrical reliability as a gate dielectric material. Capacitor test structures were electrically stressed, and the resulting impact on the physical structure was analyzed using atomic force microscopy. The volume of material removed in a DBD event is found, and the energy required (Ereq) to vaporize the volume was calculated. It is found that Ereq is proportional to the average electrical energy dissipated in the capacitor during breakdown (BD), indicating a direct correlation between damage caused during DBD and the current flow at BD location. In contrast to other thin film dielectrics, the 2D mica is highly susceptible to DBD even at very low current density (&lt;1 A/cm2) and the abrupt, destructive BD more resembles that of thick film dielectric breakdown. An explanation for these finding is proposed in which intercalated K+ ions agglomerate around defects generated by the electrical stressing such that the defect density increases substantially in the local vicinity of BD locations, which leads to increased current and associated Joule heating after the BD event.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166395","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}

引用次数: 0

Frequency stabilization of adiabatic temperature change in Fe50Rh50 alloy in a cyclic magnetic field of 1.2 T 1.2 T 循环磁场中 Fe50Rh50 合金绝热温度变化的频率稳定化

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-10 DOI: 10.1063/5.0222360

A. G. Gamzatov, P. A. Igoshev, A. M. Aliev, K. Qiao, F. Hu, J. Wang, B. Shen

{"title":"Frequency stabilization of adiabatic temperature change in Fe50Rh50 alloy in a cyclic magnetic field of 1.2 T","authors":"A. G. Gamzatov, P. A. Igoshev, A. M. Aliev, K. Qiao, F. Hu, J. Wang, B. Shen","doi":"10.1063/5.0222360","DOIUrl":"https://doi.org/10.1063/5.0222360","url":null,"abstract":"We present the results of direct measurements of the adiabatic temperature change (ΔTad) for the Fe50Rh50 alloy in a cyclic magnetic field (CMF) of 1.2 T. It is shown that increasing the frequency of the CMF from 1 to 30 Hz is accompanied by a shift of the position of temperature dependence ΔTad(T) maximum, Tmax, toward low temperatures. With an increase in the CMF frequency from 1 to 5 Hz, the ΔTmax value decreases by ∼12%. A further increase in frequency leads to stabilization of the effect. In the vicinity of the antiferromagnetic-ferromagnetic phase transition point TC = 370 K, ΔTad exhibits unconventional frequency behavior: while at T well above TC, the value of ΔTad monotonously decreases as frequency increases, at T = 370.4 K; an interval of frequency-independent ΔTad up to 10 Hz is observed, and at 368 K &lt; T &lt; TC, the maximum of ΔTad(f) dependence is found in the interval 1 &lt; f &lt; 10 Hz. Such behavior in the future can be applied in magnetic cooling technology due to large values of ΔTad and the frequency stability of the effect in alternating fields. The specific cooling power reaches giant values of ∼22 W/g at 20 Hz, which is comparable to the values under the same conditions for Gd −21.6 W/g. The unconventional behavior of ΔTad in the CMF is discussed in the context of the role of secondary phase localization, which leads to an enhanced internal local magnetic field and dynamic effects of ΔTad.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166396","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}

引用次数: 0

Dipole-assisted hole injection for efficient blue quantum dot light-emitting diodes 用于高效蓝色量子点发光二极管的偶极子辅助空穴注入技术

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-10 DOI: 10.1063/5.0226368

Youwei Zhang, Xiangtian Xiao, Ruiqiang Xu, Jingrui Ma, Fumin Lu, Yifan Ye, Xiaoli Zhang, Kai Wang, Xiao Wei Sun

{"title":"Dipole-assisted hole injection for efficient blue quantum dot light-emitting diodes","authors":"Youwei Zhang, Xiangtian Xiao, Ruiqiang Xu, Jingrui Ma, Fumin Lu, Yifan Ye, Xiaoli Zhang, Kai Wang, Xiao Wei Sun","doi":"10.1063/5.0226368","DOIUrl":"https://doi.org/10.1063/5.0226368","url":null,"abstract":"Quantum dot light-emitting diodes (QLEDs) present commercial potential and application prospects in both lighting and display technologies. Blue quantum dots (QDs) possess a substantial bandgap and a profound valence band. The significant potential barrier between blue quantum dots and the hole transport layer leads to an imbalance in charge transfer, thereby adversely impacting the device performance. Self-assembled monolayers are attractive for carrier transport. Here, a dynamic self-assembly method is introduced, doping [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) into Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) to form electric dipoles at interfaces, realizing better energy level alignment and hole injection rate. The maximum external quantum efficiency rises from 8.77% to 17.26% with 2PACz: PEDOT:PSS strategy, representing a twofold enhancement. This result demonstrates that small molecules undergo dynamic self-assembled bilateral motions during crystallization process, aligning energy levels and passivating interfacial trap states, thereby endowing blue QLEDs with high brightness and high efficiency. This work offers a viable pathway for broader applications of blue QLEDs.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166401","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}

引用次数: 0

Design of shape memory alloys with low hysteresis via multiple phase coexistence 通过多相共存设计低滞后的形状记忆合金

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-10 DOI: 10.1063/5.0206923

Deqing Xue, Qian Zuo, Yan Pan, Guojun Zhang

引用次数: 0

High-performing organic/quantum dot hybrid upconversion device based on a single-component near-infrared-sensitive layer 基于单组分近红外敏感层的高性能有机/量子点混合上转换器件

IF 4 2区物理与天体物理

Applied Physics Letters Pub Date : 2024-09-10 DOI: 10.1063/5.0228406

Ke Wang, Yuanhong Hu, Lixiang Chen, Haijun Jiang, Haohong Jiang, Xingwen Tan, Qiaoming Zhang, Yanlian Lei

{"title":"High-performing organic/quantum dot hybrid upconversion device based on a single-component near-infrared-sensitive layer","authors":"Ke Wang, Yuanhong Hu, Lixiang Chen, Haijun Jiang, Haohong Jiang, Xingwen Tan, Qiaoming Zhang, Yanlian Lei","doi":"10.1063/5.0228406","DOIUrl":"https://doi.org/10.1063/5.0228406","url":null,"abstract":"A donor/acceptor (D/A) heterojunction with an interfacial energetic offset is demonstrated to enable efficient exciton dissociation in organic photodetectors and upconversion devices (UCDs). Unfortunately, this approach usually encounters complicated optimization procedures and interfacial instability. Herein, we present an alternative strategy for achieving high-performing UCDs by utilizing an organic single-component near-infrared (NIR)-sensitive layer instead of a D/A heterojunction. The showcased UCD is constructed by vertically stacking an organic single-component Y6 NIR-detection unit and a quantum dot light-emitting unit. Due to the high dielectric constant and low exciton binding energy of the non-fullerene acceptor Y6, free carriers are directly and spontaneously generated upon NIR light excitation. As a result, the single-component UCD achieves a low light detection capability of 2.5 μW/cm2, a fast refresh rate of &gt;3.8 × 104, and a high resolution exceeding 1100 dpi, providing a stable optical response to high-frequency NIR signals and high-quality NIR imaging.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166358","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}

引用次数: 0