Характеристики pin-структуры с дискретно металлизированной поверхностью i-области

Introduction. Currently, an interest in improving pin-structures continues to be the focus of attention of developers of electronic devices. Devices that use controlled pin-structures include: non-volatile memory, static voltage protection device, pin-diodes with adjustable characteristics, etc. However, insufficient attention is paid to the issue of controlling the characteristics of pin-structures by using discrete metallization on the surface of i-region.Aim. Investigation of the influence of discrete metallization of the surface of i-region on static and dynamic characteristics of pin-structure, defect compensation, and efficiency control of the pin-photodetector.Materials and methods. The pin-structure under study consisted of p + -boron-doped region; n + -phosphorusdoped region; i-phosphorus-doped region; semi-insulating substrate; metallization of the substrate; polysilicon control gate; and a silicon oxide dielectric layer. Two-dimensional numerical analysis of the potential distribution, of the concentration of free charge carriers and currents was performed in the Synopsys Sentaurus TCAD environment.Results. Two-dimensional analysis of discretely metallized pin-structures was performed. The stresses applied to the gates of i-region that compensated the influence of defects formed by electron irradiation were determined. Four pin-photodetector structures were modeled, in which the control gates were performed in the form of metal–dielectric–semiconductor structure. The possibility of increasing the sensitivity of the pinphotodetector by applying the corresponding potentials to the gates was demonstrated.Conclusion. An effect of discrete metallization of i-region of the pin-structure was investigated. A method for correcting of the characteristics of the irradiated pin-diode to the initial characteristics was proposed. It makes possible to use such diodes in electronics with high requirements for operating in areas with high radiation. The design of a high-sensitivity photodetector with control gates on the surface of i-region and with the structure of low alloy i-region split into two regions (p- and n–type conductivity) was proposed.Введение. В настоящее время интерес к совершенствованию pin-структур продолжает оставаться в центре внимания разработчиков электронных устройств. К устройствам, в которых используются такие структуры, можно отнести энергонезависимую память, устройство защиты от статического напряжения, pin-диоды с регулируемыми характеристиками и др. Однако вопросу управления характеристиками pin-структур посредством использования дискретной металлизации на поверхности i-области уделено недостаточное внимание.Цель работы. Исследование влияния дискретной металлизации поверхности i-области на статические и динамические характеристики pin-структуры, компенсацию дефектов, управление эффективностью pinфотодетектора.Материалы и методы. Исследуемая pin-структура состоит из p+-области, легированной бором; n+- области, легированной фосфором; i-области, легированной фосфором; полуизолирующей подложки; металлизации подложки; управляющего затвора из поликремния; слоя диэлектрика из оксида кремния. Двумерный численный анализ распределения потенциала, концентрации свободных носителей заряда и токов выполнялся в среде Synopsys Sentaurus TCAD.Результаты. Выполнен двумерный анализ дискретно металлизированных pin-структур. Определены напряжения, подаваемые на затворы i-области, компенсирующие влияние дефектов, образованных электронным облучением. Проведено моделирование четырех структур pin-фотодетектора, в которых управляющие затворы выполнены в виде структуры металл–диэлектрик–полупроводник. Показана возможность увеличения чувствительности pin-фотодетектора подачей соответствующих потенциалов на затворы.Заключение. Исследовано влияние дискретной металлизации i-области pin-структуры. Предложен метод коррекции характеристик облученного pin-диода до исходных характеристик. Тем самым появляется возможность использовать такие диоды в электронике с высокими требованиями к работе в зонах с повышенной радиацией. Предложена конструкция фотодетектора повышенной чувствительности с управляющими затворами на поверхности i-области и с разделением структуры низколегированной i-области на две области р- и n-типов проводимости

The Characteristics of the pin-Structure with a Discrete Metallic Surface i-Region

Introduction. Currently, an interest in improving pin-structures continues to be the focus of attention of developers of electronic devices. Devices that use controlled pin-structures include: non-volatile memory, static voltage protection device, pin-diodes with adjustable characteristics, etc. However, insufficient attention is paid to the issue of controlling the characteristics of pin-structures by using discrete metallization on the surface of i-region.Aim. Investigation of the influence of discrete metallization of the surface of i-region on static and dynamic characteristics of pin-structure, defect compensation, and efficiency control of the pin-photodetector.Materials and methods. The pin-structure under study consisted of p + -boron-doped region; n + -phosphorusdoped region; i-phosphorus-doped region; semi-insulating substrate; metallization of the substrate; polysilicon control gate; and a silicon oxide dielectric layer. Two-dimensional numerical analysis of the potential distribution, of the concentration of free charge carriers and currents was performed in the Synopsys Sentaurus TCAD environment.Results. Two-dimensional analysis of discretely metallized pin-structures was performed. The stresses applied to the gates of i-region that compensated the influence of defects formed by electron irradiation were determined. Four pin-photodetector structures were modeled, in which the control gates were performed in the form of metal–dielectric–semiconductor structure. The possibility of increasing the sensitivity of the pinphotodetector by applying the corresponding potentials to the gates was demonstrated.Conclusion. An effect of discrete metallization of i-region of the pin-structure was investigated. A method for correcting of the characteristics of the irradiated pin-diode to the initial characteristics was proposed. It makes possible to use such diodes in electronics with high requirements for operating in areas with high radiation. The design of a high-sensitivity photodetector with control gates on the surface of i-region and with the structure of low alloy i-region split into two regions (p- and n–type conductivity) was proposed

Synthesis and photovoltaic properties of new donor-acceptor benzodithiophene-containing copolymers

Four new alternating narrow band-gap copolymers containing benzodithiophene, 4,8-dithiophen-2-yl-benzo[1,2-c;4,5-c'-bis[1,2,5]thiadiazole, 4,9-bis(thiophen-2-yl)-6,7-di(2-ethylhexyl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline, 5,8-dibromo-2,3-bis(5-octylthiophen-2-yl)quinoxaline, and 4,7-bis(5-bromothiophen-2-yl)benzo[1,2,5] thiadiazole units are synthesized under Stille reaction conditions. The structures, molecular masses, and physical properties of the copolymers are studied via H-1 NMR spectroscopy, GPC, cyclic voltammetry, and thermomechanical and thermogravimetric analyses. The polymers show solubility and a broad absorption region (with the band gap in the range from 0.81 to 1.53 eV). All of the polymers are photostable in air, and their levels of the highest occupied molecular orbital vary from -4.98 to -5.30 eV. Polymer solar cells based on these copolymers as donors and fullerene PC60BM as an acceptor show open-circuit voltages in the range 0.16-0.61 V, and the efficiencies of the devices are in the range 0.02-0.49%