TY - THES A1 - Slobodskyy, Anatoliy T1 - Diluted magnetic semiconductor Resonant Tunneling Structures for spin manipulation T1 - Verdünnt magnetische Halbleiter Resonante Tunnel-Strukturen für Spin Manipulation N2 - In this work we investigate magnetic resonant tunneling diode (RTD) structures for spin manipulation. All-II-VI semiconductor RTD structures based on [Zn,Be]Se are grown by molecular beam epitaxy. We observe a strong, magnetic field induced, splitting of the resonance peaks in the I-V characteristics of RTDs with [Zn,Mn]Se diluted magnetic semiconductors (DMS) quantum well. The splitting saturates at high fields and has strong temperature dependence. A phonon replica of the resonance is also observed and has similar behaviour to the peak. We develop a model based on the giant Zeeman splitting of the spin levels in the DMS quantum well in order to explain the magnetic field induced behaviour of the resonance. N2 - In dieser Arbeit werden magnetische resonante Tunneldioden (RTD) hinsichtlich ihrer Eignung zur Spin-Manipulation untersucht. [Zn, Be]Se basierende II-VI RTD-Strukturen wurden mittels Molekularstrahlepitaxie gewachsen. Man beobachtet eine starke, vom Magnetfeld induzierte Aufspaltung der Resonanz in der U-I Kennlinie derjenigen RTDs, die über einen Quantentrog aus [Zn, Mn]Se verdünnt magnetischen Halbleiter (DMS) verfügen. Diese Aufspaltung hat eine starke Temperaturabhängigkeit und erreicht bei hohen Feldern eine Sättigung. Eine Phononen-Replika der Resonanz wird ebenfalls beobachtet und hat ähnliche Eigenschaften wie die Resonanz selbst. Es wird ein Modell entwickelt, welches auf der Giant-Zeeman-Aufspaltung der Spin-Aufgespalteten Niveaus des DMS-Quantentrogs basiert, um das magnetfeldabhängige Verhalten der Resonanz zu erklären. KW - Resonanz-Tunneldiode KW - Semimagnetischer Halbleiter KW - Magnetoelektronik KW - spintronik KW - spin Injektion KW - verdünnt magnetische Halbleiter KW - resonante Tunneldioden KW - spintronics KW - spin injection KW - diluted magnetic semiconductors KW - resonant tunneling diode Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-18263 ER - TY - THES A1 - Hartmann, Fabian T1 - Elektrooptische Transporteigenschaften und stochastisch aktivierte Prozesse Resonanter Tunneldioden T1 - Electro-optical and transport properties and stochastically activated processes of resonant tunneling diodes N2 - Im Rahmen der vorliegenden Arbeit wurden elektrooptische Transporteigenschaften und stochastisch aktivierte Prozesse Resonanter Tunneldioden (RTDs) bei Raumtemperatur untersucht. Die RTDs wurden auf dem III-V Halbleitermaterialsystem AlGaAs/GaAs durch Molekularstrahlepitaxie, Elektronenstrahllithographie und trockenchemischen Ätztechniken hergestellt. Im Bereich des negativen differentiellen Leitwerts konnte bistabi-les Schalten und hierbei stochastisch aktivierte Dynamik nichtlinearer Systeme untersucht werden. Die Flächenabhängigkeit der Ätzrate konnte ausgenutzt werden, um RTDs mit einem Stamm und zwei Transportästen zu realisieren, welche hinsichtlich ihrer optischen und elektrischen Eigenschaften untersucht wurden. Im ersten experimentellen Abschnitt 3.1 werden die elektrischen Transporteigenschaften Resonanter Tunneldioden bei Raum-temperatur und die Flächenabhängigkeit des kohärenten und nicht-kohärenten Elektronen-transports analysiert. Die Realisierung universeller logischer Gatter (NOR und NAND) und deren Rekonfigurierbarkeit durch einen externen Kontrollparameter wird in Abschnitt 3.2 gezeigt. In Abschnitt 3.3 wird die Lichtsensitivität Resonanter Tunneldioden als Photode-tektoren für den sichtbaren Wellenlängenbereich und in Abschnitt 3.4 für die Telekommu-nikationswellenlänge bei λ = 1,3 µm demonstriert. N2 - In this thesis, electro-optical transport properties and stochastically-activated processes of resonant tunneling diodes (RTDs) were investigated at room temperature. The RTDs were prepared on the basis of AlGaAs/GaAs heterostructures by molecular beam epitaxy, elec-tron beam lithography and dry chemical etching techniques. In the region of negative dif-ferential conductance (NDC) bistable RTD switching was achieved by exploiting the load line effect in combination with stochastically-activated dynamics of nonlinear systems. The surface dependence of the etching rate was exploited in order to realize RTDs with a stem and two transport branches, which were studied with respect to their optical and electrical properties. In the first section of the experimental part, electrical transport properties of resonant tunneling diodes at room temperature and the area dependence of the coherent and non-coherent electron transport properties are described. The realization of universal logic gates (NAND and NOR) and their reconfigurability by external control parameters is then demonstrated in Section 3.2. The light sensitivity of resonant tunneling diode photo-detectors was studied for the visible wavelength range and for the telecommunication wavelength at λ = 1.3 µm, in Section 3.3, and 3.4, respectively. KW - Resonanz-Tunneldiode KW - resonant tunneling diode KW - Resonanztunneldiode KW - noise KW - stochastic resonance KW - photo detector KW - Rauschen KW - Stochastische Resonanz KW - Lichtsensor KW - Elektrooptische Eigenschaft KW - Tunneldiode Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-90876 ER - TY - JOUR A1 - Rothmayr, Florian A1 - Guarin Castro, Edgar David A1 - Hartmann, Fabian A1 - Knebl, Georg A1 - Schade, Anne A1 - Höfling, Sven A1 - Koeth, Johannes A1 - Pfenning, Andreas A1 - Worschech, Lukas A1 - Lopez-Richard, Victor T1 - Resonant tunneling diodes: mid-infrared sensing at room temperature JF - Nanomaterials N2 - Resonant tunneling diode photodetectors appear to be promising architectures with a simple design for mid-infrared sensing operations at room temperature. We fabricated resonant tunneling devices with GaInAsSb absorbers that allow operation in the 2–4 μm range with significant electrical responsivity of 0.97 A/W at 2004 nm to optical readout. This paper characterizes the photosensor response contrasting different operational regimes and offering a comprehensive theoretical analysis of the main physical ingredients that rule the sensor functionalities and affect its performance. We demonstrate how the drift, accumulation, and escape efficiencies of photogenerated carriers influence the electrostatic modulation of the sensor's electrical response and how they allow controlling the device's sensing abilities. KW - resonant tunneling diode KW - mid-infrared sensing KW - photosensor Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267152 SN - 2079-4991 VL - 12 IS - 6 ER - TY - JOUR A1 - Pfenning, Andreas A1 - Krüger, Sebastian A1 - Jabeen, Fauzia A1 - Worschech, Lukas A1 - Hartmann, Fabian A1 - Höfling, Sven T1 - Single-photon counting with semiconductor resonant tunneling devices JF - Nanomaterials N2 - Optical quantum information science and technologies require the capability to generate, control, and detect single or multiple quanta of light. The need to detect individual photons has motivated the development of a variety of novel and refined single-photon detectors (SPDs) with enhanced detector performance. Superconducting nanowire single-photon detectors (SNSPDs) and single-photon avalanche diodes (SPADs) are the top-performer in this field, but alternative promising and innovative devices are emerging. In this review article, we discuss the current state-of-the-art of one such alternative device capable of single-photon counting: the resonant tunneling diode (RTD) single-photon detector. Due to their peculiar photodetection mechanism and current-voltage characteristic with a region of negative differential conductance, RTD single-photon detectors provide, theoretically, several advantages over conventional SPDs, such as an inherently deadtime-free photon-number resolution at elevated temperatures, while offering low dark counts, a low timing jitter, and multiple photon detection modes. This review article brings together our previous studies and current experimental results. We focus on the current limitations of RTD-SPDs and provide detailed design and parameter variations to be potentially employed in next-generation RTD-SPD to improve the figure of merits of these alternative single-photon counting devices. The single-photon detection capability of RTDs without quantum dots is shown. KW - single-photon detectors KW - resonant tunneling diode KW - photon counting KW - III–V semiconductor devices Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281922 SN - 2079-4991 VL - 12 IS - 14 ER -