We previously developed an AlSiO/AlN‐interlayer gate stack formed on c‐plane GaN metal‐oxide‐semiconductor (MOS) devices to enhance the interface of the gate insulator. By utilizing this gate stack structure, we obtained a channel mobility of over 200 cm2/Vs on c‐plane. However, the threshold voltage was negative because of the polarization charge at the AlN/GaN interface. This study extends the application of this gate stack structure to the nonpolar m‐plane, which is obtained from a trench sidewall. We successfully achieve both a high channel mobility of 150 cm2/Vs and a threshold voltage of 1.3 V, normally‐off operation. This achievement holds significant promise for the gate structure of a GaN trench‐gate MOS field‐effect transistor. The limiting factor of the channel mobility is Coulomb scattering in a low electric field, whereas surface roughness scattering is dominant in a higher field.This article is protected by copyright. All rights reserved.
我们之前开发了一种在 c 平面氮化镓金属氧化物半导体（MOS）器件上形成的 AlSiO/AlN 夹层栅极堆栈，以增强栅极绝缘体的界面。利用这种栅极堆栈结构，我们在 c 平面上获得了超过 200 cm2/Vs 的沟道迁移率。然而，由于 AlN/GaN 界面的极化电荷，阈值电压为负。本研究将这种栅极叠层结构的应用扩展到了非极性 m 面，即通过沟槽侧壁获得的 m 面。我们成功地实现了 150 cm2/Vs 的高沟道迁移率和 1.3 V 的正常关断工作阈值电压。这一成果为氮化镓沟槽栅 MOS 场效应晶体管的栅极结构带来了重大希望。沟道迁移率的限制因素是低电场下的库仑散射，而表面粗糙度散射在高电场下占主导地位。本文受版权保护。
{"title":"A High Channel Mobility and a Normally‐off Operation of a Vertical GaN MOSFET Using an AlSiO/AlN Gate Stack Structure on m‐plane Trench Sidewall","authors":"Masakazu Kanechika, Kenji Ito, Tetsuo Narita, Kazuyoshi Tomita, Shiro Iwasaki, Daigo Kikuta, Tetsu Kachi","doi":"10.1002/pssr.202400010","DOIUrl":"https://doi.org/10.1002/pssr.202400010","url":null,"abstract":"We previously developed an AlSiO/AlN‐interlayer gate stack formed on <jats:italic>c</jats:italic>‐plane GaN metal‐oxide‐semiconductor (MOS) devices to enhance the interface of the gate insulator. By utilizing this gate stack structure, we obtained a channel mobility of over 200 cm<jats:sup>2</jats:sup>/Vs on <jats:italic>c</jats:italic>‐plane. However, the threshold voltage was negative because of the polarization charge at the AlN/GaN interface. This study extends the application of this gate stack structure to the nonpolar <jats:italic>m</jats:italic>‐plane, which is obtained from a trench sidewall. We successfully achieve both a high channel mobility of 150 cm<jats:sup>2</jats:sup>/Vs and a threshold voltage of 1.3 V, normally‐off operation. This achievement holds significant promise for the gate structure of a GaN trench‐gate MOS field‐effect transistor. The limiting factor of the channel mobility is Coulomb scattering in a low electric field, whereas surface roughness scattering is dominant in a higher field.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"30 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140197923","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}
While present trends in commercial PV are set on a‐Si/c‐Si heterojunctions and promising perovskites, the chalcogenides still attract interest as an excellent candidate for coming multi‐ and heterojunction devices with perovskites. Continuously enhanced over the years, typical metastabilities in thin film devices still remain, causing issues under outdoor operation. Unfortunately, qualitative assessment in commercial PV is solely focused on data at the maximum power point of its operation, whether in simple on‐site PV plant monitoring or following latest standards for certified laboratory testing, thus metastabilities merely register as undefined power fluctuations. We show in this study that dark current characteristics are a simple and yet field‐fit method, to identify metastable changes and take suitable counter measures. With this study, using commercial CdTe and CIGS showcase modules of various manufacturers and production generations, we demonstrate how dark current characteristics allow to pin‐point physical changes of the individual module, between its pristine state, outdoor operation, dark degradation and stabilization, like a fingerprint. Using the two‐diode model, we show that alterations to respective regimes of the characteristic can be assigned to typical defects, defining the module’s current state, and be used to it as a guide to evaluate its recuperation via preconditioning treatments.This article is protected by copyright. All rights reserved.
{"title":"Metastability in Dark Current Diode Characteristics of Chalcogenide Photovoltaic Modules","authors":"Bettina Friedel","doi":"10.1002/pssr.202300239","DOIUrl":"https://doi.org/10.1002/pssr.202300239","url":null,"abstract":"While present trends in commercial PV are set on a‐Si/c‐Si heterojunctions and promising perovskites, the chalcogenides still attract interest as an excellent candidate for coming multi‐ and heterojunction devices with perovskites. Continuously enhanced over the years, typical metastabilities in thin film devices still remain, causing issues under outdoor operation. Unfortunately, qualitative assessment in commercial PV is solely focused on data at the maximum power point of its operation, whether in simple on‐site PV plant monitoring or following latest standards for certified laboratory testing, thus metastabilities merely register as undefined power fluctuations. We show in this study that dark current characteristics are a simple and yet field‐fit method, to identify metastable changes and take suitable counter measures. With this study, using commercial CdTe and CIGS showcase modules of various manufacturers and production generations, we demonstrate how dark current characteristics allow to pin‐point physical changes of the individual module, between its pristine state, outdoor operation, dark degradation and stabilization, like a fingerprint. Using the two‐diode model, we show that alterations to respective regimes of the characteristic can be assigned to typical defects, defining the module’s current state, and be used to it as a guide to evaluate its recuperation via preconditioning treatments.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"29 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140197704","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}
Lei Yang, Mingkun Huang, Yue Wang, Yuanhao Kang, Le Wang, Niumiao Zhang
In this work, the PVP‐assisted CdS/PbI2 heterojunction UV‐Visible Photodetector was constructed by the sol‐gel spin coating method. The X‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) demonstrated the synthesis and successful complexation of PVP, CdS, and PbI2. The UV‐Visible absorption spectroscopy and UV photoelectron spectroscopy (UPS) measurements of CdS and PbI2 were carried out to prove that the CdS and PbI2 form a type II heterojunction. Compared with pure CdS film photodetector, the CdS (PVP)/PbI2 heterojunction photodetector has self‐powered characteristics, and exhibits excellent photoconductivity in the UV‐Visible with higher switching ratios, detection rates, and faster response times of 1.1 × 105, 9.77 × 1011 Jones and 20 ms, respectively, which has great potential in the field of UV‐Visible self‐powered photodetector.This article is protected by copyright. All rights reserved.
{"title":"High‐Performance of Self‐Powered UV‐Visible CdS (PVP)/PbI2 Heterojunction Photodetector","authors":"Lei Yang, Mingkun Huang, Yue Wang, Yuanhao Kang, Le Wang, Niumiao Zhang","doi":"10.1002/pssr.202400009","DOIUrl":"https://doi.org/10.1002/pssr.202400009","url":null,"abstract":"In this work, the PVP‐assisted CdS/PbI<jats:sub>2</jats:sub> heterojunction UV‐Visible Photodetector was constructed by the sol‐gel spin coating method. The X‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) demonstrated the synthesis and successful complexation of PVP, CdS, and PbI<jats:sub>2</jats:sub>. The UV‐Visible absorption spectroscopy and UV photoelectron spectroscopy (UPS) measurements of CdS and PbI<jats:sub>2</jats:sub> were carried out to prove that the CdS and PbI<jats:sub>2</jats:sub> form a type II heterojunction. Compared with pure CdS film photodetector, the CdS (PVP)/PbI<jats:sub>2</jats:sub> heterojunction photodetector has self‐powered characteristics, and exhibits excellent photoconductivity in the UV‐Visible with higher switching ratios, detection rates, and faster response times of 1.1 × 10<jats:sup>5</jats:sup>, 9.77 × 10<jats:sup>11</jats:sup> Jones and 20 ms, respectively, which has great potential in the field of UV‐Visible self‐powered photodetector.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"25 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140197634","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}
Chuan Peng, Han He, Hao Huang, Yongyuan Shang, Zipeng Feng, Zhipeng Zhang, Chunlan Wang, Bingsuo Zou, Liu Xingqiang
Polycrystalline indium gallium oxide has been widely studied in the domain of oxide thin film transistors (TFTs) due to its high mobility. However, there are few researches focus on amorphous IGO (a‐IGO), which has the advantage of large area display. Herein, high‐performance a‐IGO TFTs are demonstrated by magnetron sputtering method with simple process. The efficiency of a‐IGO TFTs fabricated under various conditions are evaluated, and a‐IGO TFTs prepared by 27 nm thin films grown at 220 °C have the best electrical properties. It exhibits the mobility of 35 cm2 V‐1 s‐1, threshold voltage of 0.5 V, subthreshold swing of 0.8 V/dec, and the on/off current ratio over 106. This is due to the precise control of the deposition energy state by temperature during sputtering and the influence of the semiconductor layer thickness on the distribution of the accumulation layer. The results present here demonstrate a simple fabrication method for high‐performance amorphous oxide thin film transistors, providing a new option for display driver circuits.This article is protected by copyright. All rights reserved.
{"title":"High performance amorphous IGO TFTs grown at low temperature","authors":"Chuan Peng, Han He, Hao Huang, Yongyuan Shang, Zipeng Feng, Zhipeng Zhang, Chunlan Wang, Bingsuo Zou, Liu Xingqiang","doi":"10.1002/pssr.202300457","DOIUrl":"https://doi.org/10.1002/pssr.202300457","url":null,"abstract":"Polycrystalline indium gallium oxide has been widely studied in the domain of oxide thin film transistors (TFTs) due to its high mobility. However, there are few researches focus on amorphous IGO (<jats:italic>a</jats:italic>‐IGO), which has the advantage of large area display. Herein, high‐performance <jats:italic>a</jats:italic>‐IGO TFTs are demonstrated by magnetron sputtering method with simple process. The efficiency of <jats:italic>a</jats:italic>‐IGO TFTs fabricated under various conditions are evaluated, and <jats:italic>a</jats:italic>‐IGO TFTs prepared by 27 nm thin films grown at 220 °C have the best electrical properties. It exhibits the mobility of 35 cm<jats:sup>2</jats:sup> V<jats:sup>‐1</jats:sup> s<jats:sup>‐1</jats:sup>, threshold voltage of 0.5 V, subthreshold swing of 0.8 V/dec, and the on/off current ratio over 10<jats:sup>6</jats:sup>. This is due to the precise control of the deposition energy state by temperature during sputtering and the influence of the semiconductor layer thickness on the distribution of the accumulation layer. The results present here demonstrate a simple fabrication method for high‐performance amorphous oxide thin film transistors, providing a new option for display driver circuits.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"26 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140166464","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}
Chengtao Xia, Ziwei Wang, Shuming Jiang, Ran Ji, Linlin Lu, Deren Yang, Xiangyang Ma
The visible and near‐infrared electroluminescence (EL) from the light‐emitting device (LED) based on the erbium (Er)‐doped Ta2O5 (Ta2O5:Er)/SiO2/Si structure is reported in this study. Wherein, an ∽10 nm thick SiO2 intermediate layer serves as an energy plateau for forming hot electrons, which initially transport from Si via trap‐assisted tunneling mechanism under sufficiently forward bias with the negative voltage connecting with Si. The hot electrons impact‐excite the Er3+ ions incorporated into the Ta2O5 host, leading to the Er‐related EL from the aforementioned LED. It is found that the 750 °C ‐ annealed Ta2O5:Er films are desirable to act as the light‐emitting component. Despite that the Er‐related photoluminescence from the Ta2O5:Er film becomes stronger in turn with the Er‐doping content increasing from nominal 0.75, 1.5 to 3 mol %, it is the Ta2O5:Er film with Er‐doping content of nominal 1.5 mol % rather than 3 mol % that enables the LED to exhibit the strongest EL. Based on the EL lifetime measurement and the structural characterizations, it is believed that the enhanced non‐radiative interactions among the Er3+ ions and the substantial amorphousness of Ta2O5 host caused by the nominal 3 mol % Er‐doping are responsible for the weakened EL as mentioned above.This article is protected by copyright. All rights reserved.
本研究报告了基于掺铒 Ta2O5（Ta2O5:Er）/SiO2/Si 结构的发光器件（LED）发出的可见光和近红外电致发光（EL）。其中，∽10 nm 厚的 SiO2 中间层是形成热电子的能量高原，在与 Si 相连的负电压下，热电子最初通过阱辅助隧道机制从 Si 传输。热电子撞击并激发掺杂在 Ta2O5 主成分中的 Er3+ 离子，从而导致上述 LED 发出与 Er 有关的 EL。研究发现，750 °C退火的Ta2O5:Er薄膜可用作发光元件。尽管随着掺铒含量从标称的 0.75、1.5 到 3 摩尔%的增加，Ta2O5:Er 薄膜发出的与铒有关的光致发光依次变强，但标称掺铒含量为 1.5 摩尔%而不是 3 摩尔%的 Ta2O5:Er 薄膜使 LED 显示出最强的 EL。根据电致发光寿命的测量结果和结构特征，我们认为，Er3+离子之间非辐射性相互作用的增强，以及标称的 3 摩尔% Er 掺杂造成的 Ta2O5 主基的大量非晶性，是上述电致发光减弱的原因。本文受版权保护。
{"title":"Electroluminescence from Silicon‐Based Light‐Emitting Devices with Erbium‐Doped Ta2O5 Films","authors":"Chengtao Xia, Ziwei Wang, Shuming Jiang, Ran Ji, Linlin Lu, Deren Yang, Xiangyang Ma","doi":"10.1002/pssr.202400045","DOIUrl":"https://doi.org/10.1002/pssr.202400045","url":null,"abstract":"The visible and near‐infrared electroluminescence (EL) from the light‐emitting device (LED) based on the erbium (Er)‐doped Ta<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> (Ta<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>:Er)/SiO<jats:sub>2</jats:sub>/Si structure is reported in this study. Wherein, an ∽10 nm thick SiO<jats:sub>2</jats:sub> intermediate layer serves as an energy plateau for forming hot electrons, which initially transport from Si via trap‐assisted tunneling mechanism under sufficiently forward bias with the negative voltage connecting with Si. The hot electrons impact‐excite the Er<jats:sup>3+</jats:sup> ions incorporated into the Ta<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> host, leading to the Er‐related EL from the aforementioned LED. It is found that the 750 °C ‐ annealed Ta<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>:Er films are desirable to act as the light‐emitting component. Despite that the Er‐related photoluminescence from the Ta<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>:Er film becomes stronger in turn with the Er‐doping content increasing from nominal 0.75, 1.5 to 3 mol %, it is the Ta<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>:Er film with Er‐doping content of nominal 1.5 mol % rather than 3 mol % that enables the LED to exhibit the strongest EL. Based on the EL lifetime measurement and the structural characterizations, it is believed that the enhanced non‐radiative interactions among the Er<jats:sup>3+</jats:sup> ions and the substantial amorphousness of Ta<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> host caused by the nominal 3 mol % Er‐doping are responsible for the weakened EL as mentioned above.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"2013 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140151993","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}
Wei Xin, Xiang-min Yu, Kun Zhou, Shaoxiong Li, Yang Yu
The preparation of Fock states is important for quantum information storage and processing. Here we present a two‐step protocol with topological protection for multi‐photon Fock states synthesizing in a circuit QED architecture. Due to photon number‐dependent vacuum Rabi splitting, the dynamics of the Jaynes‐Cummings ladder in the resonant regime can be equivalent to a spin‐1/2 chain while a multi‐frequency microwave pulse is applied. Based on the topologically assisted quantum state transfer technique, multi‐photon Fock states can be conditionally generated. Our method significantly reduces the complexity of experimental manipulation compared with previous multi‐step methods and is more robust as a result of topological protection. Furthermore, the protocol indicates that the circuit QED architecture could potentially provide a platform to explore the exotic phase in condensed matter.This article is protected by copyright. All rights reserved.
Fock 态的制备对于量子信息的存储和处理非常重要。在这里，我们提出了一种在电路 QED 架构中合成多光子 Fock 态的具有拓扑保护功能的两步协议。由于光子数依赖于真空拉比分裂，当应用多频微波脉冲时，杰恩-康明斯阶梯在共振机制下的动力学可以等同于自旋-1/2 链。基于拓扑辅助量子态转移技术，可以有条件地产生多光子福克态。与以往的多步骤方法相比，我们的方法大大降低了实验操作的复杂性，并且由于拓扑保护而更加稳健。此外，该协议还表明，电路 QED 架构有可能为探索凝聚态物质中的奇异相提供一个平台。本文受版权保护。
{"title":"Topologically protected synthesizing of Fock states in a circuit QED architecture","authors":"Wei Xin, Xiang-min Yu, Kun Zhou, Shaoxiong Li, Yang Yu","doi":"10.1002/pssr.202300478","DOIUrl":"https://doi.org/10.1002/pssr.202300478","url":null,"abstract":"The preparation of Fock states is important for quantum information storage and processing. Here we present a two‐step protocol with topological protection for multi‐photon Fock states synthesizing in a circuit QED architecture. Due to photon number‐dependent vacuum Rabi splitting, the dynamics of the Jaynes‐Cummings ladder in the resonant regime can be equivalent to a spin‐1/2 chain while a multi‐frequency microwave pulse is applied. Based on the topologically assisted quantum state transfer technique, multi‐photon Fock states can be conditionally generated. Our method significantly reduces the complexity of experimental manipulation compared with previous multi‐step methods and is more robust as a result of topological protection. Furthermore, the protocol indicates that the circuit QED architecture could potentially provide a platform to explore the exotic phase in condensed matter.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"165 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140151995","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}
Robert Armitage, Zhongmin Ren, Mark Holmes, Joseph Flemish
Red InGaN has attracted much attention recently for microLED display applications. However, the consequences of spectral broadening are often overlooked and many of the published spectra do not meet display gamut requirements. We focus on maximizing the red InGaN radiance with a spectrum capable of meeting the DCI‐P3 standard (dominant wavelength of ∽615 nm). The maximum radiance for LEDs meeting said requirement is obtained at 20 A/cm2 and corresponds to 4% WPE in large‐area encapsulated devices. The WPE can be increased to 12.5% using epitaxy of lower In concentration driven at 2 A/cm2. We also report data for microLEDs fabricated from similar red InGaN epitaxy. No size dependence of the IQE or spectra are observed down to the smallest sizes studied (∽2 microns). We have further leveraged our expertise with red InGaN and nitride tunnel junctions to demonstrate polychromatic microLEDs with independent control of red, green, and blue emission within single pixels of 9x12 micron dimensions. These devices are grown in a single growth run on the same sapphire substrate wafer using methods proven in high‐volume epitaxy manufacturing.This article is protected by copyright. All rights reserved.
{"title":"True‐Red InGaN Light‐Emitting Diodes for Display Applications","authors":"Robert Armitage, Zhongmin Ren, Mark Holmes, Joseph Flemish","doi":"10.1002/pssr.202400012","DOIUrl":"https://doi.org/10.1002/pssr.202400012","url":null,"abstract":"Red InGaN has attracted much attention recently for microLED display applications. However, the consequences of spectral broadening are often overlooked and many of the published spectra do not meet display gamut requirements. We focus on maximizing the red InGaN radiance with a spectrum capable of meeting the DCI‐P3 standard (dominant wavelength of ∽615 nm). The maximum radiance for LEDs meeting said requirement is obtained at 20 A/cm<jats:sup>2</jats:sup> and corresponds to 4% WPE in large‐area encapsulated devices. The WPE can be increased to 12.5% using epitaxy of lower In concentration driven at 2 A/cm<jats:sup>2</jats:sup>. We also report data for microLEDs fabricated from similar red InGaN epitaxy. No size dependence of the IQE or spectra are observed down to the smallest sizes studied (∽2 microns). We have further leveraged our expertise with red InGaN and nitride tunnel junctions to demonstrate polychromatic microLEDs with independent control of red, green, and blue emission within single pixels of 9x12 micron dimensions. These devices are grown in a single growth run on the same sapphire substrate wafer using methods proven in high‐volume epitaxy manufacturing.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"74 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140152085","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}
Intrinsic defects and their concentrations in hexagonal boron nitride play a key role in single photon emission. This study explores the optical properties of large‐area multilayer h–BN‐on‐sapphire grown by metalorganic chemical vapor deposition. Based on our detailed spectroscopic characterization using both cathodoluminescence and photoluminescence measurements, the material is devoid of random single‐point defects instead of a few clustered complex defects. The emission spectra of the measurements confirm a record‐low defect concentration of ∽104 cm‐2. Post‐annealing, no significant changes are observed in the measured spectra and the defect concentrations remain unaltered. Through cathodoluminescence and photoluminescence spectroscopy, we identify an optically active boron vacancy spin defect and reveal a novel complex defect combination arising from carbon impurities. This complex defect, previously unreported, signifies a unique aspect of our material. Our findings contribute to the understanding of defect‐induced optical properties in h–BN films, providing insights for potential applications in quantum information science.This article is protected by copyright. All rights reserved.
{"title":"Optical properties of low‐defect large‐area h–BN for quantum applications","authors":"Shrivatch Sankar, Shantanu Saha, Jia-Shiang Chen, Shih-Po Chien, YannWen Lan, Xuedan Ma, Michael Snure, Shamsul Arafin","doi":"10.1002/pssr.202400034","DOIUrl":"https://doi.org/10.1002/pssr.202400034","url":null,"abstract":"Intrinsic defects and their concentrations in hexagonal boron nitride play a key role in single photon emission. This study explores the optical properties of large‐area multilayer h–BN‐on‐sapphire grown by metalorganic chemical vapor deposition. Based on our detailed spectroscopic characterization using both cathodoluminescence and photoluminescence measurements, the material is devoid of random single‐point defects instead of a few clustered complex defects. The emission spectra of the measurements confirm a record‐low defect concentration of ∽10<jats:sup>4</jats:sup> cm<jats:sup>‐2</jats:sup>. Post‐annealing, no significant changes are observed in the measured spectra and the defect concentrations remain unaltered. Through cathodoluminescence and photoluminescence spectroscopy, we identify an optically active boron vacancy spin defect and reveal a novel complex defect combination arising from carbon impurities. This complex defect, previously unreported, signifies a unique aspect of our material. Our findings contribute to the understanding of defect‐induced optical properties in h–BN films, providing insights for potential applications in quantum information science.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"24 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140156383","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}
{"title":"The Interplay between Strain, Sn Content, and Temperature on Spatially Dependent Bandgap in Ge1−xSnx Microdisks","authors":"Ignatii Zaitsev, Agnieszka Anna Corley-Wiciak, Cedric Corley-Wiciak, Marvin Hartwig Zoellner, Carsten Richter, Edoardo Zatterin, Michele Virgilio, Beatriz Martín-García, Davide Spirito, Costanza Lucia Manganelli","doi":"10.1002/pssr.202470005","DOIUrl":"https://doi.org/10.1002/pssr.202470005","url":null,"abstract":"","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"18 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140129473","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}
Frank Brunner, Enrico Brusaterra, Eldad Bahat‐Treidel, Oliver Hilt, Markus Weyers
The development of processes for epitaxial growth of vertical gallium nitride (GaN) drift layers enabling 1.2 kV breakdown voltage on low‐cost sapphire substrates is presented in comparison to GaN bulk substrates. The targeted blocking capability demands drift layers with a thickness of 10 μm and low but controllable n‐type doping. Using a growth rate of 2.5 μm h−1 the concentration of unintentionally incorporated carbon is sufficiently low to adjust the n‐type carrier concentration to ≈1 × 1016 cm−3 for all types of substrates. To assess GaN drift region properties in terms of forward bias conductivity and reverse bias blocking strength, a quasi‐vertical p‐n‐diode structure is utilized. Bow reduction of GaN‐on‐sapphire structures is achieved using a stealth laser scribing process. Breakdown voltages higher than 1600 V and a specific on‐state resistance as low as 0.7 mΩ cm2 are obtained with diodes fabricated on GaN substrates. Similar structures grown on sapphire show breakdown voltages of about 1300 V due to higher levels of current leakage. Comparing different types of substrates, a direct correlation between dislocation density in the drift layer with the leakage current in p‐n diodes is deduced.
介绍了在低成本蓝宝石衬底上外延生长垂直氮化镓（GaN）漂移层的工艺开发情况，与氮化镓块状衬底相比，该漂移层的击穿电压可达 1.2 kV。目标击穿能力要求漂移层的厚度为 10 μm，并具有低但可控的 n 型掺杂。采用 2.5 μm h-1 的生长速率，无意掺入的碳浓度足够低，可以将所有类型衬底的 n 型载流子浓度调整到 ≈1 × 1016 cm-3。为了评估氮化镓漂移区在正向偏压电导率和反向偏压阻断强度方面的特性，采用了准垂直 p-n 二极管结构。通过隐形激光划线工艺实现了蓝宝石上氮化镓结构的弓形减小。在氮化镓衬底上制造的二极管可获得高于 1600 V 的击穿电压和低至 0.7 mΩ cm2 的特定导通电阻。在蓝宝石上生长的类似结构由于漏电流水平较高，击穿电压约为 1300 V。通过比较不同类型的衬底，可以推断出漂移层中的位错密度与 p-n 二极管的漏电流之间存在直接的相关性。
{"title":"GaN Drift Layers on Sapphire and GaN Substrates for 1.2 kV Class Vertical Power Devices","authors":"Frank Brunner, Enrico Brusaterra, Eldad Bahat‐Treidel, Oliver Hilt, Markus Weyers","doi":"10.1002/pssr.202400013","DOIUrl":"https://doi.org/10.1002/pssr.202400013","url":null,"abstract":"The development of processes for epitaxial growth of vertical gallium nitride (GaN) drift layers enabling 1.2 kV breakdown voltage on low‐cost sapphire substrates is presented in comparison to GaN bulk substrates. The targeted blocking capability demands drift layers with a thickness of 10 μm and low but controllable n‐type doping. Using a growth rate of 2.5 μm h<jats:sup>−1</jats:sup> the concentration of unintentionally incorporated carbon is sufficiently low to adjust the n‐type carrier concentration to ≈1 × 10<jats:sup>16</jats:sup> cm<jats:sup>−3</jats:sup> for all types of substrates. To assess GaN drift region properties in terms of forward bias conductivity and reverse bias blocking strength, a quasi‐vertical p‐n‐diode structure is utilized. Bow reduction of GaN‐on‐sapphire structures is achieved using a stealth laser scribing process. Breakdown voltages higher than 1600 V and a specific on‐state resistance as low as 0.7 mΩ cm<jats:sup>2</jats:sup> are obtained with diodes fabricated on GaN substrates. Similar structures grown on sapphire show breakdown voltages of about 1300 V due to higher levels of current leakage. Comparing different types of substrates, a direct correlation between dislocation density in the drift layer with the leakage current in p‐n diodes is deduced.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":"16 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140098128","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：