Zhiqin Li, Li Liu, Minxin Li, Mingliang Tian, Hui Han, Hui Li
Twisted homostructures provide a versatile platform to engineer interlayer coupling and collective orders via moiré superlattices. While the effectiveness of the moiré potential in modulating charge density waves (CDWs) has been established through spectroscopic techniques, systematic investigations through electrical transport measurements remain scarce. Here, by leveraging interfacial moiré superlattices, we characterize the phase transition between the nearly commensurate CDW state and the incommensurate CDW state in twisted 1T-TaS2 homostructures. A two-step transition is observed in twisted 1T-TaS2 homostructures, which is in marked contrast to the single and smooth transition of pristine sample. The two–step transition behavior persists over twist angles from 0° to 58° and for excitation currents spanning two orders of magnitude. These features are consistent with a moiré potential induced periodic pinning landscape for nearly commensurate CDW domain walls at the twisted interface. Our results establish twist angle as an effective control knob for engineering CDWs in layered materials and open routes to moiré superlattice based device concepts.
{"title":"Twist angle control of charge density wave transitions in 1T–TaS2 homostructures","authors":"Zhiqin Li, Li Liu, Minxin Li, Mingliang Tian, Hui Han, Hui Li","doi":"10.1063/5.0303061","DOIUrl":"https://doi.org/10.1063/5.0303061","url":null,"abstract":"Twisted homostructures provide a versatile platform to engineer interlayer coupling and collective orders via moiré superlattices. While the effectiveness of the moiré potential in modulating charge density waves (CDWs) has been established through spectroscopic techniques, systematic investigations through electrical transport measurements remain scarce. Here, by leveraging interfacial moiré superlattices, we characterize the phase transition between the nearly commensurate CDW state and the incommensurate CDW state in twisted 1T-TaS2 homostructures. A two-step transition is observed in twisted 1T-TaS2 homostructures, which is in marked contrast to the single and smooth transition of pristine sample. The two–step transition behavior persists over twist angles from 0° to 58° and for excitation currents spanning two orders of magnitude. These features are consistent with a moiré potential induced periodic pinning landscape for nearly commensurate CDW domain walls at the twisted interface. Our results establish twist angle as an effective control knob for engineering CDWs in layered materials and open routes to moiré superlattice based device concepts.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"52 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961907","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}
Miniaturized InGaN micro-light-emitting diodes suffer reliability drifts that are not fully captured by conventional optical/electrical reporting. This study shows that, after 500-h direct current (DC) operation at 40 A cm−2, sub-10-μm devices exhibit a dominant-wavelength red-shift under fixed current that is non-thermal, as verified by <0.5 °C infrared thermography. A capacitance-decomposition model resolves the measured capacitance–voltage (C–V) dispersion into physically distinct trap ensembles and yields sub-40-ns response times, identifying shallow, sidewall-related traps as primary actors. The extracted trap dynamics quantitatively account for the increased series resistance, efficiency peak suppression, and weakened quantum-confined Stark effect screening responsible for the spectral shift. These results establish a mechanism-driven picture of reliability in miniaturized InGaN emitters and provide a general methodology for trap dynamics quantification in wide-bandgap optoelectronics. A display-driving implication is briefly noted, with details in the supplementary material.
小型化的InGaN微型发光二极管遭受可靠性漂移，这是传统光学/电学报告无法完全捕获的。本研究表明，在40 A cm−2的直流（DC）下工作500小时后，10 μm以下的器件在固定电流下表现出非热的主波长红移，并通过&；lt；0.5°C红外热成像进行了验证。电容分解模型将测量到的电容-电压（C-V）色散分解成物理上不同的陷阱集合，并产生低于40-ns的响应时间，识别出与侧壁相关的浅层陷阱是主要因素。提取的陷阱动态定量地解释了增加的串联电阻，效率峰抑制和减弱的量子限制斯塔克效应筛选导致的光谱移位。这些结果建立了小型化InGaN发射器可靠性的机制驱动图，并为宽禁带光电子学中的陷阱动力学量化提供了一般方法。简要地指出了显示驱动的含义，并在补充材料中详细说明。
{"title":"Shallow trap dynamics and non-thermal spectral shift in sub-10- μ m InGaN micro-LEDs","authors":"Runan Zhang, Yujia Gong, Liang Zhang, Shulin Chen, Shuming Zhang, Jiahao Kang, Ze Yuan","doi":"10.1063/5.0301981","DOIUrl":"https://doi.org/10.1063/5.0301981","url":null,"abstract":"Miniaturized InGaN micro-light-emitting diodes suffer reliability drifts that are not fully captured by conventional optical/electrical reporting. This study shows that, after 500-h direct current (DC) operation at 40 A cm−2, sub-10-μm devices exhibit a dominant-wavelength red-shift under fixed current that is non-thermal, as verified by &lt;0.5 °C infrared thermography. A capacitance-decomposition model resolves the measured capacitance–voltage (C–V) dispersion into physically distinct trap ensembles and yields sub-40-ns response times, identifying shallow, sidewall-related traps as primary actors. The extracted trap dynamics quantitatively account for the increased series resistance, efficiency peak suppression, and weakened quantum-confined Stark effect screening responsible for the spectral shift. These results establish a mechanism-driven picture of reliability in miniaturized InGaN emitters and provide a general methodology for trap dynamics quantification in wide-bandgap optoelectronics. A display-driving implication is briefly noted, with details in the supplementary material.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"267 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962424","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}
This study presents an atomistic nonequilibrium Green's function (NEGF) approach for modeling radiation-induced charge loss in floating-gate flash memories, which become increasingly vulnerable to radiation effects as device features shrink. Nonradiative charge-carrier recombination at localized deep-level defect centers is treated by coupling the defect Green's function to delocalized interface states derived from a two-probe tight-binding description, via multiphonon-scattering self-energies. Using oxygen vacancies as representative deep-level traps, the trap-assisted tunneling current under retention conditions is calculated by integrating the NEGF formalism within a drift-diffusion solver. This NEGF framework significantly improves agreement with experimental data from heavy-ion irradiation, and provides insights beyond semiclassical models. These findings underscore the necessity of atomistic, fully quantum treatments for reliable assessment and design of radiation-hardened nonvolatile memory technologies.
{"title":"Atomistic nonequilibrium Green's function study of radiation-induced charge loss in floating gate flash memories","authors":"X. C. Chen, L. Li","doi":"10.1063/5.0297525","DOIUrl":"https://doi.org/10.1063/5.0297525","url":null,"abstract":"This study presents an atomistic nonequilibrium Green's function (NEGF) approach for modeling radiation-induced charge loss in floating-gate flash memories, which become increasingly vulnerable to radiation effects as device features shrink. Nonradiative charge-carrier recombination at localized deep-level defect centers is treated by coupling the defect Green's function to delocalized interface states derived from a two-probe tight-binding description, via multiphonon-scattering self-energies. Using oxygen vacancies as representative deep-level traps, the trap-assisted tunneling current under retention conditions is calculated by integrating the NEGF formalism within a drift-diffusion solver. This NEGF framework significantly improves agreement with experimental data from heavy-ion irradiation, and provides insights beyond semiclassical models. These findings underscore the necessity of atomistic, fully quantum treatments for reliable assessment and design of radiation-hardened nonvolatile memory technologies.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"81 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961906","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}
Transition metal doping in perovskite nanocrystals is an important means to regulate their photophysical properties. In particular, the underlying concentration effect and optical process deserve further study. Herein, we investigate the phenomenon of continuous redshift in manganese-doped perovskite nanocrystals' spectra with the Mn2+ doping concentration. The results from experiment combined with density functional theory show that the spectral redshift primarily results from the heightened emission of Mn2+–Mn2+ dimers and the reduced contribution of isolated Mn2+ as the concentration of Mn2+ increases. What is more, appropriate introduction of Cu2+ ions with a Cu to Pb molar ratio of 1:1 can increase the formation energy of Mn-related defects, facilitate the formation of Mn2+–Mn2+ dimers, and simultaneously inhibit the non-radiative recombination process caused by the close spacing of Mn2+ ions, thereby avoiding the occurrence of fluorescence quenching, thus the redshift of spectra is significant in the presence of Cu2+ ion. These findings enhance our comprehension of the photoluminescence mechanism related to spectral redshift in nanocrystals doped with transition metals.
{"title":"Cu2+-facilitated formation of Mn2+–Mn2+ dimers inducing redshift of Mn2+ emission in Co-doped perovskite nanocrystals","authors":"Yunfeng Wang, Chenenze Jiang, Yunru Chen, Xing Hu, Tingfu Pang, Huan Tang, Shuanglai Liu, Manjing Wang, Xiaosheng Tang, Wenxia Zhang","doi":"10.1063/5.0311121","DOIUrl":"https://doi.org/10.1063/5.0311121","url":null,"abstract":"Transition metal doping in perovskite nanocrystals is an important means to regulate their photophysical properties. In particular, the underlying concentration effect and optical process deserve further study. Herein, we investigate the phenomenon of continuous redshift in manganese-doped perovskite nanocrystals' spectra with the Mn2+ doping concentration. The results from experiment combined with density functional theory show that the spectral redshift primarily results from the heightened emission of Mn2+–Mn2+ dimers and the reduced contribution of isolated Mn2+ as the concentration of Mn2+ increases. What is more, appropriate introduction of Cu2+ ions with a Cu to Pb molar ratio of 1:1 can increase the formation energy of Mn-related defects, facilitate the formation of Mn2+–Mn2+ dimers, and simultaneously inhibit the non-radiative recombination process caused by the close spacing of Mn2+ ions, thereby avoiding the occurrence of fluorescence quenching, thus the redshift of spectra is significant in the presence of Cu2+ ion. These findings enhance our comprehension of the photoluminescence mechanism related to spectral redshift in nanocrystals doped with transition metals.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"26 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961991","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}
Benefiting from the excellent optothermal properties of diamond crystals and the absence of spatial hole burning effects in stimulated Raman scattering, diamond Raman lasers hold significant advantages in achieving high-performance, single-frequency laser output. Moreover, they also demonstrate great potential in generating single-frequency vortex beams at a special wavelength. In this work, we demonstrate a single-frequency diamond Raman vortex laser by introducing simple off-axis cavity mirror misalignment into a two-mirror standing-wave diamond Raman oscillator. We calculate and analyze the output modes and transmitted signals of the diamond Raman oscillator under different off-axis conditions. Experimentally, we demonstrate resonant pumping of the diamond Raman oscillator under different off-axis conditions using the Pound–Drever–Hall frequency stabilization technique. This facilitated the generation of the single-frequency fundamental HG00 mode as well as higher-order HG01 and HG02 modes, each with low thresholds. Through extra-cavity astigmatic mode conversion, we further generated diamond-based vortex beams with topological charges of 1 and 2. Benefiting from the inherent advantages of diamond Raman lasers, this system holds significant potential for wavelength extension and power scaling of single-frequency vortex laser beams.
{"title":"Single-frequency Raman vortex beam enabled by a frequency-locked off-axis diamond cavity","authors":"Zhenxu Bai, Hui Chen, Junhong Chen, Wenqiang Fan, Yunpeng Cai, Jie Ding, Srinivasa Rao Allam, Zhi-Han Zhu, Yulei Wang, Zhiwei Lu, Takashige Omatsu","doi":"10.1063/5.0294558","DOIUrl":"https://doi.org/10.1063/5.0294558","url":null,"abstract":"Benefiting from the excellent optothermal properties of diamond crystals and the absence of spatial hole burning effects in stimulated Raman scattering, diamond Raman lasers hold significant advantages in achieving high-performance, single-frequency laser output. Moreover, they also demonstrate great potential in generating single-frequency vortex beams at a special wavelength. In this work, we demonstrate a single-frequency diamond Raman vortex laser by introducing simple off-axis cavity mirror misalignment into a two-mirror standing-wave diamond Raman oscillator. We calculate and analyze the output modes and transmitted signals of the diamond Raman oscillator under different off-axis conditions. Experimentally, we demonstrate resonant pumping of the diamond Raman oscillator under different off-axis conditions using the Pound–Drever–Hall frequency stabilization technique. This facilitated the generation of the single-frequency fundamental HG00 mode as well as higher-order HG01 and HG02 modes, each with low thresholds. Through extra-cavity astigmatic mode conversion, we further generated diamond-based vortex beams with topological charges of 1 and 2. Benefiting from the inherent advantages of diamond Raman lasers, this system holds significant potential for wavelength extension and power scaling of single-frequency vortex laser beams.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"80 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961992","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}
In this work, we present the first investigation into the impact mechanism of Fe doping tails on the radio frequency (RF) switching performance of AlGaN/gallium nitride (GaN) high electron mobility transistors (HEMTs). It is illustrated that a thicker unintentionally doped (UID) GaN layer combined with a thinner Fe-doped buffer layer significantly reduces Fe concentration in the near-channel region of the UID GaN layer. HEMTs with weaker Fe doping tails exhibit superior RF switching performance. This phenomenon occurs as the Fe tailing effect during high-power RF switch operation aggravates the dynamic resistance degradation of the series HEMT and modifies the channel potential distribution, which in turn induces a large vertical component capacitance in the shunt HEMT. Fabricated switch devices with 500 nm gate length on the optimized epitaxial structure demonstrated outstanding performance: Pmax = 32 dBm at 3.6 GHz under −10 V gate bias, and Pmax > 38 dBm with OIP3 = 56 dBm at −20 V gate bias. These experimental results demonstrate that controlled Fe tail effect engineering enables HEMTs to achieve both high-power handling and high linearity simultaneously, demonstrating a viable approach for developing high-performance RF switches compatible with Fe-doped buffer power amplifiers.
{"title":"Modulation of Fe doping tail for high CW power handling and OIP3 in HEMT-based RF switches compatible with PA co-integration","authors":"Xu Zou, Meng Zhang, Ling Yang, Yutong Jiang, Qian Yu, Chunzhou Shi, Shiming Li, Wenze Gao, Qingyuan Chang, Weiyu Ren, Haolun Sun, Bin Hou, Mei Wu, Hao Lu, Xiaohua Ma, Yue Hao","doi":"10.1063/5.0300235","DOIUrl":"https://doi.org/10.1063/5.0300235","url":null,"abstract":"In this work, we present the first investigation into the impact mechanism of Fe doping tails on the radio frequency (RF) switching performance of AlGaN/gallium nitride (GaN) high electron mobility transistors (HEMTs). It is illustrated that a thicker unintentionally doped (UID) GaN layer combined with a thinner Fe-doped buffer layer significantly reduces Fe concentration in the near-channel region of the UID GaN layer. HEMTs with weaker Fe doping tails exhibit superior RF switching performance. This phenomenon occurs as the Fe tailing effect during high-power RF switch operation aggravates the dynamic resistance degradation of the series HEMT and modifies the channel potential distribution, which in turn induces a large vertical component capacitance in the shunt HEMT. Fabricated switch devices with 500 nm gate length on the optimized epitaxial structure demonstrated outstanding performance: Pmax = 32 dBm at 3.6 GHz under −10 V gate bias, and Pmax &gt; 38 dBm with OIP3 = 56 dBm at −20 V gate bias. These experimental results demonstrate that controlled Fe tail effect engineering enables HEMTs to achieve both high-power handling and high linearity simultaneously, demonstrating a viable approach for developing high-performance RF switches compatible with Fe-doped buffer power amplifiers.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"7 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962022","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}
Yuanhao Zhu, Xiuming Dou, Shaoteng Wu, Li He, Kun Ding, Baoquan Sun, Jun-Wei Luo
Germanium (Ge) has long been regarded as a promising laser material for silicon photonics due to its quasi-direct bandgap to make up for the deficiency of indirect bandgap silicon, but its energy band structure under pressure remains puzzling. Here, we study the pressure-dependent photoluminescence (PL) of Ge compressed in a diamond anvil cell to reveal its energy band structure up to 3.89 GPa. Unlike the earlier reported results studied by absorption, the effect of high pressure on bandgaps can be studied for the same sample and the determinations of bandgap positions are not influenced by the sample thickness and the interference pattern. The PL peak related to X–Γ bandgap transition was observed with pressure coefficient of −12.4 ± 2.1 meV/GPa. We unambiguously show that the L- and Γ-valleys move upward while the X–valley moves downward in energy with increasing pressure, with a Γ–X crossover observed at an onset pressure of 0.74 GPa, and then a L–X crossover takes place near 2.85 GPa. These findings provide experimental evidence for identification of the band structure of Ge, deepening the understanding of pressure-induced bandgap modification and conduction band valley crossover.
{"title":"Pressure-dependent photoluminescence study of band structure in germanium","authors":"Yuanhao Zhu, Xiuming Dou, Shaoteng Wu, Li He, Kun Ding, Baoquan Sun, Jun-Wei Luo","doi":"10.1063/5.0306355","DOIUrl":"https://doi.org/10.1063/5.0306355","url":null,"abstract":"Germanium (Ge) has long been regarded as a promising laser material for silicon photonics due to its quasi-direct bandgap to make up for the deficiency of indirect bandgap silicon, but its energy band structure under pressure remains puzzling. Here, we study the pressure-dependent photoluminescence (PL) of Ge compressed in a diamond anvil cell to reveal its energy band structure up to 3.89 GPa. Unlike the earlier reported results studied by absorption, the effect of high pressure on bandgaps can be studied for the same sample and the determinations of bandgap positions are not influenced by the sample thickness and the interference pattern. The PL peak related to X–Γ bandgap transition was observed with pressure coefficient of −12.4 ± 2.1 meV/GPa. We unambiguously show that the L- and Γ-valleys move upward while the X–valley moves downward in energy with increasing pressure, with a Γ–X crossover observed at an onset pressure of 0.74 GPa, and then a L–X crossover takes place near 2.85 GPa. These findings provide experimental evidence for identification of the band structure of Ge, deepening the understanding of pressure-induced bandgap modification and conduction band valley crossover.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"57 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961909","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}
AlGaInP-based red micro-light-emitting diodes (micro-LEDs) with lateral dimensions of 28 × 52 µm2 were fabricated on transparent glass substrates via solder bonding for high-performance transparent displays. The fabricated devices exhibited excellent spectral stability, featuring a record-low wavelength redshift coefficient of less than 0.126 nm/K. Notably, the glass-substrate-integrated micro-LED arrays achieved an optical transmittance of 52.6% alongside a record-high luminance of 1.5 × 105 nits, underscoring their great potential for practical transparent display applications.
{"title":"Red micro-LEDs on glass substrates for ultrahigh-luminance (>105 nits) transparent displays","authors":"Changdong Tong, Wenjie He, Jinfeng Zhang, Bo Li, Yurong Dai, Guolong Chen, Yijun Lu, Tingzhu Wu, Zhong Chen, Weijie Guo","doi":"10.1063/5.0311701","DOIUrl":"https://doi.org/10.1063/5.0311701","url":null,"abstract":"AlGaInP-based red micro-light-emitting diodes (micro-LEDs) with lateral dimensions of 28 × 52 µm2 were fabricated on transparent glass substrates via solder bonding for high-performance transparent displays. The fabricated devices exhibited excellent spectral stability, featuring a record-low wavelength redshift coefficient of less than 0.126 nm/K. Notably, the glass-substrate-integrated micro-LED arrays achieved an optical transmittance of 52.6% alongside a record-high luminance of 1.5 × 105 nits, underscoring their great potential for practical transparent display applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"13 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961910","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}
Gallium oxide (Ga2O3) transparent conductive electrodes and power-device contact layers are critical components for Ga2O3-based electronics. However, the intrinsically low electron mobility (μ) of the (100) plane, which is preferred for large-scale substrate production, under high carrier concentration (n) has hindered device performance and practical deployment. To overcome this bottleneck, we employed unintentionally miscut (100) substrates and optimized thermal and kinetic conditions to achieve step-flow homoepitaxy with ideal surface morphology. Following the elimination of surface Si contamination, in situ Si doping was performed utilizing silicon tetrachloride (SiCl4). SiCl4 proved highly effective for fabricating high-n homoepilayers, yielding films with high crystalline quality, low surface roughness, and more than 80% optical transmittance in the 260–800 nm range. Notably, at a SiCl4 doping flux of 10.4 nmol/min, the homoepilayer exhibited outstanding electrical properties (n = 1.32 × 1019 cm−3, μ = 55.5 cm2 V−1 s−1). These findings not only outperform previously reported results for (100) homoepilayers grown on intentionally miscut substrates but also rival the performance of state-of-the-art (010) plane epilayers.
{"title":"Achieving high carrier concentration β-Ga2O3 epilayers via MOCVD using SiCl4 as dopant","authors":"Yaoping Lu, Zhenni Yang, Titao Li, Duanyang Chen, Hongji Qi, Haizhong Zhang, Xiaoqiang Lu","doi":"10.1063/5.0304883","DOIUrl":"https://doi.org/10.1063/5.0304883","url":null,"abstract":"Gallium oxide (Ga2O3) transparent conductive electrodes and power-device contact layers are critical components for Ga2O3-based electronics. However, the intrinsically low electron mobility (μ) of the (100) plane, which is preferred for large-scale substrate production, under high carrier concentration (n) has hindered device performance and practical deployment. To overcome this bottleneck, we employed unintentionally miscut (100) substrates and optimized thermal and kinetic conditions to achieve step-flow homoepitaxy with ideal surface morphology. Following the elimination of surface Si contamination, in situ Si doping was performed utilizing silicon tetrachloride (SiCl4). SiCl4 proved highly effective for fabricating high-n homoepilayers, yielding films with high crystalline quality, low surface roughness, and more than 80% optical transmittance in the 260–800 nm range. Notably, at a SiCl4 doping flux of 10.4 nmol/min, the homoepilayer exhibited outstanding electrical properties (n = 1.32 × 1019 cm−3, μ = 55.5 cm2 V−1 s−1). These findings not only outperform previously reported results for (100) homoepilayers grown on intentionally miscut substrates but also rival the performance of state-of-the-art (010) plane epilayers.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"30 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962011","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}
Ziyue Qin, Ke Jiang, Bingxiang Wang, Chunyue Zhang, Zhiming Shi, Kexi Liu, Xianjun Wang, Boyu Hu, Shunpeng Lv, Yuping Jia, Mingrui Liu, Shanli Zhang, Xiaojuan Sun, Dabing Li
The low p-doping efficiency of AlGaN due to its high activation energy limits the advancement of deep ultraviolet optoelectronics. The quantum engineering method has provided a new insight to address the challenge of acceptor activation in Al-rich AlGaN. As its unique valence band offset, the distribution of acceptor and band edge states in the barrier and well determines the acceptor activation efficiency. Here, we proposed a model for reducing the acceptor activation energy in quantum-structured p-AlGaN and provided experimental validation. By tuning the reactor pressure, we prepared periodic quantum-structured p-AlGaN with different cycles successfully. Compared to long-period quantum structures, short-period quantum structures introduce more band offsets, enhancing the wavefunction overlap between the acceptor states and the band edge states, thereby significantly promoting acceptor activation. Ultimately, we achieved an ultrathin quantum-structure p-AlGaN with an average Al content of ∼77% and a periodic thickness of 2.7 nm, reaching a record-low resistivity value of about 5.4 Ω·cm. Additionally, it is demonstrated that short-period quantum structures can facilitate hole injection in deep ultraviolet light-emitting diodes, effectively improving their external quantum efficiency. This study offers an effective p-doping strategy for Al-rich AlGaN and paves the way for applications of deep ultraviolet optoelectronics.
{"title":"Quantum structure for efficient p-doping of AlGaN with Al content over 70%","authors":"Ziyue Qin, Ke Jiang, Bingxiang Wang, Chunyue Zhang, Zhiming Shi, Kexi Liu, Xianjun Wang, Boyu Hu, Shunpeng Lv, Yuping Jia, Mingrui Liu, Shanli Zhang, Xiaojuan Sun, Dabing Li","doi":"10.1063/5.0304708","DOIUrl":"https://doi.org/10.1063/5.0304708","url":null,"abstract":"The low p-doping efficiency of AlGaN due to its high activation energy limits the advancement of deep ultraviolet optoelectronics. The quantum engineering method has provided a new insight to address the challenge of acceptor activation in Al-rich AlGaN. As its unique valence band offset, the distribution of acceptor and band edge states in the barrier and well determines the acceptor activation efficiency. Here, we proposed a model for reducing the acceptor activation energy in quantum-structured p-AlGaN and provided experimental validation. By tuning the reactor pressure, we prepared periodic quantum-structured p-AlGaN with different cycles successfully. Compared to long-period quantum structures, short-period quantum structures introduce more band offsets, enhancing the wavefunction overlap between the acceptor states and the band edge states, thereby significantly promoting acceptor activation. Ultimately, we achieved an ultrathin quantum-structure p-AlGaN with an average Al content of ∼77% and a periodic thickness of 2.7 nm, reaching a record-low resistivity value of about 5.4 Ω·cm. Additionally, it is demonstrated that short-period quantum structures can facilitate hole injection in deep ultraviolet light-emitting diodes, effectively improving their external quantum efficiency. This study offers an effective p-doping strategy for Al-rich AlGaN and paves the way for applications of deep ultraviolet optoelectronics.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"38 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145961990","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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