Pub Date : 2024-06-30DOI: 10.35848/1882-0786/ad5949
Che-Wei Hsu, Yueh-Chin Lin, Shao-Lun Lee, Kai-Wen Chen, Ying-Ciao Chen and Edward Yi Chang
In this study, AlGaN/GaN HEMTs with Au-free Ti/Al/Ni/Ti ohmic contacts were fabricated. The device presents a contact resistance (Rc) of 0.64 Ω·mm and high linearity characteristics. The two-tone measurement at 28 GHz shows that the 2 × 50 μm device exhibits an excellent third-order intercept point (OIP3) value of 41.64 dBm at VDS = 28 V, and an OIP3/PDC of 24.2. An OIP3 of 46.59 dBm was achieved when the device’s gate width was increased to 8 × 50 μm at VDS = 48 V. These results demonstrate that AlGaN/GaN HEMTs with Ti/Al/Ni/Ti ohmic contacts have potential for Ka-band applications.
{"title":"High linearity AlGaN/GaN HEMTs with Au-free Ti/Al/Ni/Ti ohmic contacts for Ka-band applications","authors":"Che-Wei Hsu, Yueh-Chin Lin, Shao-Lun Lee, Kai-Wen Chen, Ying-Ciao Chen and Edward Yi Chang","doi":"10.35848/1882-0786/ad5949","DOIUrl":"https://doi.org/10.35848/1882-0786/ad5949","url":null,"abstract":"In this study, AlGaN/GaN HEMTs with Au-free Ti/Al/Ni/Ti ohmic contacts were fabricated. The device presents a contact resistance (Rc) of 0.64 Ω·mm and high linearity characteristics. The two-tone measurement at 28 GHz shows that the 2 × 50 μm device exhibits an excellent third-order intercept point (OIP3) value of 41.64 dBm at VDS = 28 V, and an OIP3/PDC of 24.2. An OIP3 of 46.59 dBm was achieved when the device’s gate width was increased to 8 × 50 μm at VDS = 48 V. These results demonstrate that AlGaN/GaN HEMTs with Ti/Al/Ni/Ti ohmic contacts have potential for Ka-band applications.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
APbX3-type [A = CH3NH3+ (MA+), NH2CH=NH2+ (FA+), X = Cl–, Br–, I–] organic–inorganic perovskite nanocrystals (PeNCs) have superior optical properties, such as emission with a narrow full width at half maximum and emission color tunability over the entire visible range. However, blue-emitting PeNCs [APb(Br/Cl)3] exhibit low photoluminescence quantum yields owing to Cl defects, hindering their practical applications. The Cl defects induce nonradiative recombination caused by the trap levels formed deep in the band gap. Herein, we report the preparation of blue-emitting PeNCs that exhibit excellent optical properties by using NaBH4 to decrease the number of Cl defects.
{"title":"Blue-emitting perovskite nanocrystals with enhanced optical properties through using NaBH4","authors":"Mao Goto, Naoaki Oshita, Kenshin Yoshida, Takuro Iizuka, Yusaku Morikawa, Hiroto Shimizu, Ryota Kobayashi, Takayuki Chiba, Satoshi Asakura and Akito Masuhara","doi":"10.35848/1882-0786/ad52e6","DOIUrl":"https://doi.org/10.35848/1882-0786/ad52e6","url":null,"abstract":"APbX3-type [A = CH3NH3+ (MA+), NH2CH=NH2+ (FA+), X = Cl–, Br–, I–] organic–inorganic perovskite nanocrystals (PeNCs) have superior optical properties, such as emission with a narrow full width at half maximum and emission color tunability over the entire visible range. However, blue-emitting PeNCs [APb(Br/Cl)3] exhibit low photoluminescence quantum yields owing to Cl defects, hindering their practical applications. The Cl defects induce nonradiative recombination caused by the trap levels formed deep in the band gap. Herein, we report the preparation of blue-emitting PeNCs that exhibit excellent optical properties by using NaBH4 to decrease the number of Cl defects.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141530011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-06-17DOI: 10.35848/1882-0786/ad548f
Maolin Dai, Bowen Liu, Yifan Ma, Takuma Shirahata, Ruoao Yang, Zhigang Zhang, Sze Yun Set and Shinji Yamashita
We demonstrate a 783 MHz fundamental repetition rate mode-locked Er-doped all-fiber ring laser with a pulse width of 623 fs. By using carbon nanotubes saturable absorber, a relatively low self-starting pump threshold of 108 mW is achieved. The laser has a very compact footprint less than 10 cm × 10 cm, benefiting from the all-active-fiber cavity design. The robust mode-locking is confirmed by the low relative intensity noise and a long-term stability test. We propose a new scheme for generating high repetition rate femtosecond optical pulses from a compact and stable all-active-fiber ring oscillator.
{"title":"783 MHz fundamental repetition rate all-fiber ring laser mode-locked by carbon nanotubes","authors":"Maolin Dai, Bowen Liu, Yifan Ma, Takuma Shirahata, Ruoao Yang, Zhigang Zhang, Sze Yun Set and Shinji Yamashita","doi":"10.35848/1882-0786/ad548f","DOIUrl":"https://doi.org/10.35848/1882-0786/ad548f","url":null,"abstract":"We demonstrate a 783 MHz fundamental repetition rate mode-locked Er-doped all-fiber ring laser with a pulse width of 623 fs. By using carbon nanotubes saturable absorber, a relatively low self-starting pump threshold of 108 mW is achieved. The laser has a very compact footprint less than 10 cm × 10 cm, benefiting from the all-active-fiber cavity design. The robust mode-locking is confirmed by the low relative intensity noise and a long-term stability test. We propose a new scheme for generating high repetition rate femtosecond optical pulses from a compact and stable all-active-fiber ring oscillator.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141522999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-06-11DOI: 10.35848/1882-0786/ad56f8
S. Rathaur, Le Trung Hieu, Dixit Abhisek, Edward Yi Chang
This study compares Vth-instability in D-mode MIS-HEMT devices between 2-epitaxial layers, AlN/AlGaN/GaN superlattice-W1, and three-step graded AlGaN-W2. Experimental results demonstrate that W1 exhibits ∼13% less Vth-instability compared to W2, with distinct degradation regions at specific voltage ranges. With temperature variation (30°C-150°C), these regions justified and reveal small positive Vth-shifts due to electron trapping, leading to temporary degradation, followed-by negative Vth-shifts from positive charge injection, culminating in catastrophic degradation attributing impact ionization at 30°C during 0-30V gate-step stress, with permanent failure observed. Analysis indicates W1-devices are more efficient and stable. Also, both layers operate reliably till VGS=18V, with ∼3% minor Vth-instability
{"title":"Reliability assessment of high-power GaN-HEMT devices with different buffers under influence of gate bias and high-temperature tests.","authors":"S. Rathaur, Le Trung Hieu, Dixit Abhisek, Edward Yi Chang","doi":"10.35848/1882-0786/ad56f8","DOIUrl":"https://doi.org/10.35848/1882-0786/ad56f8","url":null,"abstract":"\u0000 This study compares Vth-instability in D-mode MIS-HEMT devices between 2-epitaxial layers, AlN/AlGaN/GaN superlattice-W1, and three-step graded AlGaN-W2. Experimental results demonstrate that W1 exhibits ∼13% less Vth-instability compared to W2, with distinct degradation regions at specific voltage ranges. With temperature variation (30°C-150°C), these regions justified and reveal small positive Vth-shifts due to electron trapping, leading to temporary degradation, followed-by negative Vth-shifts from positive charge injection, culminating in catastrophic degradation attributing impact ionization at 30°C during 0-30V gate-step stress, with permanent failure observed. Analysis indicates W1-devices are more efficient and stable. Also, both layers operate reliably till VGS=18V, with ∼3% minor Vth-instability","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141357695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-06-07DOI: 10.35848/1882-0786/ad4468
Shuji Hasegawa
Electronic states at the boundaries of crystals, such as surfaces, interfaces, edges, hinges, corners, and extremities, play crucial roles in emerging quantum materials, such as graphene and similar monatomic-layer materials, van der Waals crystals, and topological insulators. Electronic states at such boundaries are different from those inside the three- or two-dimensional crystals, not only because of the truncation of crystal lattices but also because of space-inversion-symmetry breaking and difference in topology in band structures across the boundaries. Such quantum materials are expected to advance energy-saving/-harvesting technology as well as quantum computing/information technology because of exotic phenomena, such as spin–momentum locking of an electron, pure spin current, dissipation-less charge current, nonreciprocal current, and possible Majorana fermions. In this review, their fundamental concepts are introduced from the viewpoint of surface physics, in which atomic and electronic structures, as well as charge/spin transport properties, are directly probed using state-of-the-art techniques.
{"title":"Surface and interface physics driven by quantum materials","authors":"Shuji Hasegawa","doi":"10.35848/1882-0786/ad4468","DOIUrl":"https://doi.org/10.35848/1882-0786/ad4468","url":null,"abstract":"Electronic states at the boundaries of crystals, such as surfaces, interfaces, edges, hinges, corners, and extremities, play crucial roles in emerging quantum materials, such as graphene and similar monatomic-layer materials, van der Waals crystals, and topological insulators. Electronic states at such boundaries are different from those inside the three- or two-dimensional crystals, not only because of the truncation of crystal lattices but also because of space-inversion-symmetry breaking and difference in topology in band structures across the boundaries. Such quantum materials are expected to advance energy-saving/-harvesting technology as well as quantum computing/information technology because of exotic phenomena, such as spin–momentum locking of an electron, pure spin current, dissipation-less charge current, nonreciprocal current, and possible Majorana fermions. In this review, their fundamental concepts are introduced from the viewpoint of surface physics, in which atomic and electronic structures, as well as charge/spin transport properties, are directly probed using state-of-the-art techniques.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-06-06DOI: 10.35848/1882-0786/ad5512
Jizhe Zhao, Jiyuan Zheng, Yubo Yang, Yinjie Liu, Xiayang Hua, Lai Wang, Z. Hao, Anran Guo, Yi Luo
While the larger photosensitive area of Geiger-mode Avalanche Photodiode (GmAPDs) enhances their detection range and signal collection, improving their utility in weak light detection, their practicality is limited by long recovery times, high afterpulsing probability (AP), and excessive jitter. Utilizing a Dynamic Memristor (DM) as a quenching resistor, this research improves the count rate of a large-size GmAPD by 100× at an overvoltage of 2.5 V, compared to a fixed resistor (FR)-quenched GmAPD. Furthermore, at 1 MHz photon pulse frequency, jitter time is reduced from 3.60 ns to 0.48 ns, and afterpulsing probability is effectively mitigated from 30.88% to 8.58%.
{"title":"Enhancing large-area Geiger-mode avalanche photodiode performance through dynamic memristor quenching: A study on improving count rate, reducing jitter, and mitigating afterpulsing","authors":"Jizhe Zhao, Jiyuan Zheng, Yubo Yang, Yinjie Liu, Xiayang Hua, Lai Wang, Z. Hao, Anran Guo, Yi Luo","doi":"10.35848/1882-0786/ad5512","DOIUrl":"https://doi.org/10.35848/1882-0786/ad5512","url":null,"abstract":"\u0000 While the larger photosensitive area of Geiger-mode Avalanche Photodiode (GmAPDs) enhances their detection range and signal collection, improving their utility in weak light detection, their practicality is limited by long recovery times, high afterpulsing probability (AP), and excessive jitter. Utilizing a Dynamic Memristor (DM) as a quenching resistor, this research improves the count rate of a large-size GmAPD by 100× at an overvoltage of 2.5 V, compared to a fixed resistor (FR)-quenched GmAPD. Furthermore, at 1 MHz photon pulse frequency, jitter time is reduced from 3.60 ns to 0.48 ns, and afterpulsing probability is effectively mitigated from 30.88% to 8.58%.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141377440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
We perform electrolyte gating using ionic crystals instead of conventional ionic liquids and gels. By applying a gate voltage and heating the ionic crystal to a liquid state, Fermi level tuning of a carbon nanotube (CNT) film was achieved. Subsequent resolidification at room temperature ensured a fixed ion distribution in the electric double layer at the tuned state. The CNT film maintained the tuned Fermi level for over 30 days, even after the gate electrode was removed. This addresses the challenges associated with handling conventional ionic liquids and is poised to revolutionise the field of electrolyte gating for nanomaterial devices.
{"title":"Electrolyte gating using ionic crystals: Demonstration of iontronics with ionic crystals","authors":"Daichi Suzuki, Yoshiyuki Nonoguchi, Yuki Kuwahara, Takeshi SAITO, Nao Terasaki","doi":"10.35848/1882-0786/ad540f","DOIUrl":"https://doi.org/10.35848/1882-0786/ad540f","url":null,"abstract":"\u0000 We perform electrolyte gating using ionic crystals instead of conventional ionic liquids and gels. By applying a gate voltage and heating the ionic crystal to a liquid state, Fermi level tuning of a carbon nanotube (CNT) film was achieved. Subsequent resolidification at room temperature ensured a fixed ion distribution in the electric double layer at the tuned state. The CNT film maintained the tuned Fermi level for over 30 days, even after the gate electrode was removed. This addresses the challenges associated with handling conventional ionic liquids and is poised to revolutionise the field of electrolyte gating for nanomaterial devices.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141267517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-05-24DOI: 10.35848/1882-0786/ad5073
Nabil Ahmed, M. Razanoelina, M. Hori, Akira Fujiwara, Yukinori Ono
Drag between the electron-layer and the hole-layer formed in a silicon-on-insulator metal-oxide-semiconductor field-effect-transistor, with the estimated interlayer distance as small as 18 nm, is investigated. The drag resistance is measured at 10 K and mapped on the plane defined by the electron density and hole density. The analysis shows that the Coulomb drag predominates over the competing virtual-phonon drag. The observed drag resistance is as large as 103 - 104 Ω, indicating strong Coulomb interaction between the electron and hole layers.
研究了在硅绝缘体金属氧化物半导体场效应晶体管中形成的电子层和空穴层之间的阻力,估计层间距离小至 18 纳米。阻力是在 10 K 条件下测量的,并绘制在电子密度和空穴密度所定义的平面上。分析表明,库仑阻力超过了相互竞争的虚声子阻力。观测到的阻力高达 103 - 104 Ω,表明电子层和空穴层之间存在很强的库仑相互作用。
{"title":"Drag of electron-hole bilayer in silicon-on-insulator metal-oxide-semiconductor field-effect transistor at low temperature","authors":"Nabil Ahmed, M. Razanoelina, M. Hori, Akira Fujiwara, Yukinori Ono","doi":"10.35848/1882-0786/ad5073","DOIUrl":"https://doi.org/10.35848/1882-0786/ad5073","url":null,"abstract":"\u0000 Drag between the electron-layer and the hole-layer formed in a silicon-on-insulator metal-oxide-semiconductor field-effect-transistor, with the estimated interlayer distance as small as 18 nm, is investigated. The drag resistance is measured at 10 K and mapped on the plane defined by the electron density and hole density. The analysis shows that the Coulomb drag predominates over the competing virtual-phonon drag. The observed drag resistance is as large as 103 - 104 Ω, indicating strong Coulomb interaction between the electron and hole layers.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141100564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-05-23DOI: 10.35848/1882-0786/ad45ae
Sosuke Iwamoto, Takayoshi Shimura, Heiji Watanabe and Takuma Kobayashi
We investigated the abundance, structures, energy levels, and spin states of oxygen-related defects in 4H-SiC on the basis of first-principles calculations. We applied a hybrid functional in the overall calculations, which gives reliable defect properties, and also considered relevant defect charge states. We identified the oxygen interstitial (Oi,1), substitutional oxygen (OC), and oxygen-vacancy (OCVSi) complex as prominent defects in n-type conditions. Among them, OCVSi was predicted as a spin-1 defect with NIR emission in a previous study. On the basis of the obtained results, we discuss the possible spin decoherence sources when employing OCVSi as a spin-to-photon interface.
我们在第一原理计算的基础上研究了 4H-SiC 中氧相关缺陷的丰度、结构、能级和自旋态。我们在整体计算中应用了混合函数,该函数给出了可靠的缺陷特性,同时还考虑了相关的缺陷电荷态。我们发现间隙氧(Oi,1)、置换氧(OC)和氧空位(OCVSi)复合物是 n 型条件下的突出缺陷。其中,OCVSi 在之前的研究中被预测为具有近红外发射的自旋-1 缺陷。根据所获得的结果,我们讨论了将 OCVSi 用作自旋光子界面时可能存在的自旋退相干源。
{"title":"Oxygen-related defects in 4H-SiC from first principles","authors":"Sosuke Iwamoto, Takayoshi Shimura, Heiji Watanabe and Takuma Kobayashi","doi":"10.35848/1882-0786/ad45ae","DOIUrl":"https://doi.org/10.35848/1882-0786/ad45ae","url":null,"abstract":"We investigated the abundance, structures, energy levels, and spin states of oxygen-related defects in 4H-SiC on the basis of first-principles calculations. We applied a hybrid functional in the overall calculations, which gives reliable defect properties, and also considered relevant defect charge states. We identified the oxygen interstitial (Oi,1), substitutional oxygen (OC), and oxygen-vacancy (OCVSi) complex as prominent defects in n-type conditions. Among them, OCVSi was predicted as a spin-1 defect with NIR emission in a previous study. On the basis of the obtained results, we discuss the possible spin decoherence sources when employing OCVSi as a spin-to-photon interface.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141152333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
High-quality epitaxial Mg3Sb2 thin films are promising thermoelectric materials to enable practical applications of compact and environmentally friendly thermoelectric conversion at room temperature. In this study, high-quality single-crystal Mg3Sb2 with high c-plane orientation were epitaxially grown directly on annealed c-Al2O3 substrates without passive layers. These thin films exhibited three times higher thermoelectric power factor than ever reported values due to high carrier mobility. The ultra-smooth surface of the annealed c-Al2O3 substrate facilitated the formation of high-quality Mg3Sb2 thin films without passive layers or polycrystalline interfaces that could be carrier scatters.
{"title":"Epitaxial growth of high-quality Mg3Sb2 thin films on annealed c-plane Al2O3 substrates and their thermoelectric properties","authors":"Akito Ayukawa, Nozomu Kiridoshi, Wakaba Yamamoto, Akira Yasuhara, Haruhiko Udono, S. Sakane","doi":"10.35848/1882-0786/ad4f4c","DOIUrl":"https://doi.org/10.35848/1882-0786/ad4f4c","url":null,"abstract":"\u0000 High-quality epitaxial Mg3Sb2 thin films are promising thermoelectric materials to enable practical applications of compact and environmentally friendly thermoelectric conversion at room temperature. In this study, high-quality single-crystal Mg3Sb2 with high c-plane orientation were epitaxially grown directly on annealed c-Al2O3 substrates without passive layers. These thin films exhibited three times higher thermoelectric power factor than ever reported values due to high carrier mobility. The ultra-smooth surface of the annealed c-Al2O3 substrate facilitated the formation of high-quality Mg3Sb2 thin films without passive layers or polycrystalline interfaces that could be carrier scatters.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141111098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}