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PL
W pracy przedstawiono wyniki badań wpływu kąta padania światła na wartości natężenia oświetlenia zmierzone przy wykorzystaniu wybranych czujników fotometrycznych. Opisano stanowisko pomiarowe oraz zaprezentowano i przedyskutowano uzyskane wyniki pomiarów. Zbadano również wpływ osłon korygujących montowanych na fotodetektorach na zmierzone wartości natężenia oświetlenia.
EN
The paper presents the results of research on the influence of the angle of incidence of light on the values of illuminance measured with the use of selected sensors with photodetectors. The measurement set-up is described and the obtained measurement results are presented and discussed. The influence of the corrective shields mounted on the photodetectors on the measured values of the illuminance is also investigated.
EN
We review recently proposed concepts of infrared and terahertz photodetectors based on graphene van der Waals heterostructures and HgTe-CdHgTe quantum well heterostructures and demonstrate their potential.
EN
In this study, the temperature influence on the spectral responsivity of a Light Emitting Diode (LED) used as a photoreceptor, combined to light source spectrum is correlated to electrical characteristics in order to propose an alternative method to estimate LED junction temperature, regardless of the absolute illumination intensity and based on the direct correlation between the integral of the product of two optical spectra and the photo-generated currents. A laboratory test bench for experimental optical measurements has been set in order to enable any characterizing of photoelectric devices in terms of spectral behaviour, in a wavelength range placed between 400–1000 nm, and of current-voltage characteristics as function of temperature by using two different illumination sources. The temperature is analysed in a range from 5°C up to 85°C, so as to evaluate thermal variation effects on the sensor performance. The photo-generated current of two LEDs with different peak wavelengths has been studied. Research has observed and mathematically analysed what follows: since the photo-generated current strictly depends on the combination between the spectral response of the photoreceptor and the lighting source response, it becomes possible to estimate indirectly the junction temperature of the LEDs by considering the ratio between the photogenerated currents obtained by using two different illumination sources. Such results may for one thing increase knowledge in the fields where LEDs are used as photo-detectors for many applications and for another, they could be extended to generic photodetectors, thus providing useful information in photovoltaic field, for instance.
EN
The acquisition of positron emission tomography (PET) pulses introduces artifacts and limits the performance of the scanner. To minimize these inadequacies, this work focuses on the design of an offset compensated digital baseline restorer (BLR) along with a two-stage hybrid interpolator. They respectively treat the incoming pulse offsets and limited temporal resolution and improve the scanner performance in terms of calculating depth of interactions and line of responses. The offset of incoming PET pulses is compensated by the BLR and then their interesting parts are selected. The selected signal portion is up-sampled with a hybrid interpolator. It is composed of an optimized weighted least-squares interpolator (WLSI) and a simplified linear interpolator. The processes of calibrating the WLSI coefficients and characterizing the BLR and the interpolator modules are described. The functionality of the proposed modules is verified with an experimental setup. Results have shown that the devised BLR effectively compensates a dynamic range of bipolar offsets. The signal selection process allows focusing only on the relevant signal part and avoids the unnecessary operations during the post-interpolation process. Additionally, the hybrid nature allows improving the signal temporal resolution with an appropriate precession at a reduced computational complexity compared to the mono-interpolationbased arithmetically complex counterparts. The component-level architectures of the BLR and the interpolator modules are also described. It promises an efficient integration of these modules in modern PET scanners while using standard and economical analog-to-digital converters and field-programmable gate arrays. It avoids the development of high-performance and expensive application-specific integrated circuits and results in a costeffective realization.
5
Content available Fast Response Hot (111) HGCDTE MWIR Detectors
EN
In this work we report simulation and experimental results for an MWIR HgCdTe photodetector designed by computer simulation and fabricated in a joint laboratory run by VIGO Sytems S.A. and Military University of Technology. The device is based on a modified N+pP+ heterostructure grown on 2”., epiready, semi-insulating (100) GaAs substrates in a horizontal MOCVD AIX 200 reactor. The devices were examined by measurements of spectral and time responses as a function of a bias voltage and operating temperatures. The time response was measured with an Optical Parametric Oscillator (OPO) as the source of ~25 ps pulses of infrared radiation, tuneable in a 1.55–16 μm spectral range. Two-stage Peltier cooled devices (230 K) with a 4.1 μm cut-off wavelength were characterized by 1.6 × 1012 cm Hz1/2/W peak detectivity and < 1 ns time constant for V > 500 mV.
PL
Technologia nowoczesnych detektorów, opartych na antymonkowych supersieciach wymaga specjalnego podejścia. Z jednej strony, podyktowane jest to ich wyrafinowaną konstrukcją, z drugiej, wynika ze specyfiki chemicznej natury półprzewodników III-V, w szczególności ich oddziaływania z tlenem. W odniesieniu do materiałów antymonkowych, pasywacja, zarówno w rozumieniu poprawy morfologii powierzchni, usunięcia tlenków resztkowych, jak i zredukowania gęstości stanów powierzchniowych, jest niezbędna i stanowi zasadniczy temat artykułu. Przedstawiono przegląd stosowanych metod i technik pasywacji detektorowych struktur supersieciowych, głównie w aspekcie ich fizyczno-chemicznego działania, a także rezultaty prac prowadzonych w tym zakresie w ITE.
EN
The modern type-II superlattice InAs/GaSb-based photodetectors require the special technological approach. This is due to both the specific reaction of GaSb and related compounds with oxygen as well as sophisticated thin strained-layer construction of IR detectors. In particular, an abrupt termination of tetrahedral GaSb and InAs crystal lattices along a given plane to form a surface leads to the formation of native oxides, and the traps at the oxide/semiconductor interface. These traps introduce energy states within the semiconductor energy gap, resulting in the Fermi level being pinned near midgap, thereby increasing the surface leakage current. Thus, in order to eliminate these problems and improve overall device performance the surface passivation is absolutely necessary. The review of the different passivation methods and techniques has been presented. The results of the research on the type-II InAs/GaSb infrared photodetectors carried out in ITE are presented as well.
EN
In this paper, formation of a nanostructure semi transparence fluoride tin oxides (FTO) by spray pyrolysis technique on porous silicon PS layer. Porous silicon PS layer was prepared by anodization of p-type silicon wafers to fabricate of the UV- Visible Fluoride-doped tin oxide /Porous silicon /p-Si heterojunction photodetector. Optical properties of FTO thin films were measured. The optical band gap of 3.77 eV for SnO2 : F for film was deduced. From (I-V) and (C-V) measurements, the barrier ØB height for FTO/PS diode was of 0.77, and the built in voltage Vbi, which was of 0.95 V. External quantum efficiency was 55 % at 500 nm which corresponding to peak responsivity of 1.15 A/W at 1 V bias. The PS band gap in the vicinity of PS/c-Si heterojunction was 1.38 eV.
EN
This article describes the stage of work associated with the implementation of a program- controlled measuring stand for recording the acoustic signals. An attempt has been made for practical implementation of the stand that uses light from a semiconductor laser, modulated by acoustic wave to obtain the information transmitted by this wave. The authors decided to build the hardware construction of the stand with the use of: a PC which serves as the controller, a DAQ card, the light emitter set with a semiconductor laser and the light receiving set capable of processing the received signal into a form suitable for a DAQ card. Moreover, additional equipment used during the examination tests is also described. The software part of the stand includes: device drivers and an application written in LabVIEW environment. The functions of signal processing and analysis, graphical and numerical presentation of the data, recording to file and reading the stored data from a file are all implemented in the application. The achieved stage of a work has been confirmed by sample measurements.
9
Content available remote Badania długoczasowe detektorów UV
PL
Przy wyborze detektorów UV do konkretnej aplikacji należy uwzględnić, że ich parametry optyczne i elektryczne mogą się zmieniać w znacznym stopniu podczas eksploatacji, w wyniku zachodzenia w ich strukturze różnorodnych procesów degradacyjnych. Najczęstszymi źródłami tych procesów są długoczasowe poddawania struktury półprzewodnikowej detektora UV wpływowi silnego promieniowania termicznego lub/i optycznego.
EN
In the selection of the UV detector to a particular application should be considered that the optical and electrical parameters may vary considerably during operation due to the overlap in the composition of a variety of degradative processes. The most common sources of these processes are long-term semiconductor structures subjected UV detector strong influence of thermal radiation and / or optical.
EN
The rigorous numerical analysis of the surface photovoltage (SPV) versus excitation UV-light intensity (Φ), from 104 to 1020 photon/(cm2s) in a metal/insulator/n-GaN structure with a negative gate voltage (VG = –2 V) was performed using a finite element method. In the simulations we assumed a continuous U-shape density distribution function Dit(E) of the interface states and n-type doping concentration ND = 1016 cm–3. The SPV signal was calculated and compared in three different characteristic regions at the interface, namely i) under the gate centre, ii) near the gate edge and iii) between the gate and ohmic contact. We attributed the differences in SPV(Φ) dependences to the influence of the interface states in terms of the initial band bending and interface recombination controlled by the gate bias. The obtained results are useful for the design of GaN-based UV-radiation photodetectors.
PL
W niniejszym artykule omówiony został projekt optycznych linii transmisyjnych pracujących z częstotliwością do 2 GHz. Linie te zostały zbudowane w Katedrze Przyrzadów Półprzewodnikowych i Optotelektronicznych Politechniki Łódzkiej, a ich dokładny opis również znajduje się w niniejszym artykule. W dalszej części artykułu przedstawione zostaly wyniki pomiarów przeprowadzone za pomocą zbudowanych optycznych linii transmisyjnych.
EN
In this paper projects of optical transmission lines operating at high frequency up to 2GHz were discussed Those lines were built in Department of Semiconductor and Optoelectronics Devices of Technical University of Lodz and their detailed description is placed in this article. In the latter part of this paper results of measurements carried out using optical transmission lines were presented.
EN
This paper mainly presents a theoretical analysis for the characteristics of quantum dot infrared photodetectors (QDIPs) and quantum wire infrared photodetectors (QRIPs). The paper introduces a unique mathematical model of solving Poisson's equations with the usage of Lambert W functions for infrared detectors' structures based on quantum effects. Even though QRIPs and QDIPs have been the subject of extensive researches and development during the past decade, it is still essential to implement theoretical models allowing to estimate the ultimate performance of those detectors such as photocurrent and its figure-of-merit detectivity vs. various parameter conditions such as applied voltage, number of quantum wire layers, quantum dot layers, lateral characteristic size, doping density, operation temperature, and structural parameters of the quantum dots (QDs), and quantum wires (QRs). A comparison is made between the computed results of the implemented models and fine agreements are observed. It is concluded from the obtained results that the total detectivity of QDIPs can be significantly lower than that in the QRIPs and main features of the QRIPs such as large gap between the induced photocurrent and dark current of QRIP which allows for overcoming the problems in the QDIPs. This confirms what is evaluated before in the literature. It is evident that by increasing the QD/QR absorption volume in QDIPs/QRIPs as well as by separating the dark current and photocurrents, the specific detectivity can be improved and consequently the devices can operate at higher temperatures. It is an interesting result and it may be benefit to the development of QDIP and QRIP for infrared sensing applications.
PL
Celem pracy było opanowanie metody szybkiej charakteryzacji fotodiod z tellurku kadmowo-rtęciowego - HgCdTe - otrzymywanych metodą MOCYD (Metal Organie Chemical Vapor Depositiori) tzn. techniką osadzania warstw na powierzchni materiałów poprzez stosowanie związków metaloorganicznych w formie gazowej oraz analiza tej metody. W pierwszej kolejności otrzymane warstwy epitaksjalne poddawano procesowi technologicznemu i w ten sposób uzyskiwano gotowe fotodiody. Dokonano też pomiarów czasu trwania poszczególnych etapów procesu technologicznego. Uzyskane detektory poddawano następnie pomiarom w celu wyznaczenia ich charakterystyk prądowo-napięciowych oraz spektralnych. Na podstawie analizy tych charakterystyk oraz z wykonanych obliczeń otrzymano parametry diod, które następnie porównano z parametrami na jakie zaprojektowano heterostruktury oraz z wartościami literaturowymi. Zarówno w tym przypadku, jak i podczas przeprowadzania procesu technologicznego dążono do jak największego zminimalizowania czasu potrzebnego na wykonanie każdego etapu przy jednoczesnym zachowaniu staranności i dokładności wykonywanych czynności. Istotą postępowania było bowiem jak najszybsze uzyskanie informacji zwrotnej dotyczącej parametrów otrzymanych heterostruktur w celu porównania ich z założeniami wstępnymi i ewentualnego szybkiego skorygowania procesu epitaksji, dążąc tym samym do jego usprawnienia.
EN
The aim of this study was to master a method for a quick characterization of mercury cadmium telluride (HgCdTe) photodiodes obtained by MOCVD (Metal Organic Chemical Vapor Deposition) method, which was achieved. First, the obtained epitaxial layers were subjected to the technological process procedures and thus complete photodiodes were fabricated. The duration of measurements of each process stage was quantified. Detectors were then measured to determine their current-voltage and spectral characteristics. On the basis of the analysis of both these characteristics and calculations, the parameters of diodes were obtained. They were subsequently compared with the parameters of designed target heterostructures and with literature values. Both here and during the process the goal was to minimize as much as possible the time needed to complete each stage, while maintaining diligence and accuracy of the performed operations. The essence was to be provided with rapid feedback concerning the parameters of the obtained heterostructures in order to compare them with the initial assumptions and, if needed to correct next epitaxy processes, aiming at their improvement.
EN
Silicon Photomultiplier (SiPM) detectors are of great interest mostly because they can operate with light levels of few photons at room temperature and have fast response with typical rise time of 2-5ns. The paper presents an integrated circuit of front-end electronics designed in CMOS technology, dedicated for Silicon Photomultiplier (SiPM) detectors. The circuits was produced in the AMS 0,35�Ým technology and preliminary test results show its high performance.
PL
Krzemowe fotodetektory cieszą sie dużym zainteresowaniem e względu na możliwość rejestracji światła w temperaturze pokojowej na poziomie pojedynczych fotonów. W artykule przestawiono układ scalony elektroniki odczytowej do krzemowych fotopowielaczy zrealizowany w technologii CMO (AMS 0,35 .m) oraz wstępne wyniki testów potwierdzające jego funkcjonalność.
PL
Artykuł przedstawia wyniki badań równoległego filtra aktywnego poprawiającego właściwości odbiornika nieliniowego, w którym wykorzystano transmisję sygnałów sterujących łączem światłowodowym. Transmisję światłowodową zrealizowano przy wykorzystaniu układu TOTO/ TORX 173 i polimerowego włókna optycznego (POF). Dotychczasowe rozwiązania wykorzystujące klasyczne łącza miedziane sprawdzały się do transmisji na odległość tylko rzędu kilkunastu centymetrów, ze względu na bardzo duże zniekształcenia wynikające z oddziaływania zewnętrznego pola elektromagnetycznego na przewody transmisyjne. Stosując optyczne łącze światłowodowe uzyskano poprawną pracę układu z możliwością odseparowania modułów sterujących na odległość rzędu 10 m, z perspektywą wydłużenia linii transmisyjnej, wykorzystując technikę WDM.
EN
The paper presents investigation results of the parallel active power filter, which improves the propriety of nonlinear receiver set. Control system is using the TOSLINK optical link transmission.The optical systems of data transmision usually be used in telecommunicational optical nets, audio-video connection or there, where assured the suitable quality of signal has to be. The light is insensitive on electromagnetic field, under regard his speed of changes and the value of field amplitude. This optical track proprieties can transfer information in subject to electromagnetic disturbance environments Fig. 4) [3]. The system control was executed in two ways. Technologically simpler was the system of individual input-output channels (Fig. 5). The more advanced WDM system (Fig. 6), was using the multiplexation and demultiplexation of optical signal broadcast with single fiber. The transoptors elimination from control systems and leaning in their place the optical broadcast system besed on TOTX/TORX 173 (Fig. 7) improves the quality of steering signal quality and increases the transmission band in comparison to integrated arrangements. The use of optical fiber separation permits on shortening the distance between module and inverter. The signal analysis from oscilloscope (Fig. 8) shows small delay, which results from the time of detection by TORX and insignificant disconnection time of TOTX. The test of optical link was executed by the optical fiber of length nearly 10 m.
16
Content available Optyczna transmisja sygnału w magistrali I2C
PL
Artykuł prezentuje zagadnienia związane z możliwością transmisji sygnału opartego o magistralę I2C poprzez optyczny system światłowodowy. Przedstawiono aplikacje umożliwiające konwersję sygnału magistrali na sygnał optyczny z wykorzystaniem konwertera P82B96. Transmisję światłowodową realizować można poprzez klasyczny układ dioda LED - fotodetektor, układy TOSLINK lub system WDM. Opracowane modelowe aplikacje optycznego łącza obsługującego sygnały magistrali I2C pozwalają na budowę rzeczywistych układów konwersji dwukierunkowego sygnału magistrali do postaci optycznej.
EN
The paper presents the problem connected with possibility of signal transmission over I2C bus through optical system. I2C is a synchronic bus through which data are sent in 8-bit frames (Fig. 3) [4]. It consists practically of two signal lines: The SDA ( data line - Serial Data Line), the SCL ( clock line - Serial Clock Line) and the ground cir-cuit (Fig. 2). The schematic diagram of a system with I2C bus is shown in Fig. 1. There three possible solutions of optical application of the bus based on use of a converter P82B96 (Fig. 4) [2] and optical fiber to transfer high-speed signals ( the speed about 3,4 Mb/s) over long data transmission lines. The simplest solution of conversion the I2C signal to optical one is a configuration using LED source (λ = 940 nm) presented in Fig. 5. The PIN-photodiode works with the maximum sensitivity of about 940 nm. There should be applied three separate optical lines, broadcasting, receiving and clock, for correct operation of this arrangement. The next configuration uses an optical transmitter TOTX173 and optical receiver TORX173 assembled to pcb (Fig. 6). They are THOSIBA elements working on the wave length of 660 nm [3]. The last proposed solution is a WDM system (Wavelength Division Multiplexing) enabling si-multaneous sending signals SCL and SDA over one optical track [1].
17
Content available remote A(III)B(V) detectors with graded active region
EN
Results of modelling and fabrication of photodetectors with composition graded active layers have been presented. Simulated and measured spectral characteristics of the proposed detectors have been shown. Advantages of such structures have been discussed with respect to conventional detectors with non-graded active areas as well as some technological problems of compositionally graded semiconductor layers.
EN
In the paper, the method of relative spectroreflectometry at using the infrared photodetectors with a wide diapason of the spectral photosensitivity is suggested. Methodical errors at exponential and power dependencies of the emissivity of an object on the wavelength are analysed. Possible design of a pyrometer for measurements of temperature of hot metals is described and attractiveness of quantum-well laser diodes and superlattice photodetectors based on the GaSb compounds is discussed.
PL
W pracy zaproponowano metodę spektrofotometrii porównawczej z wykorzystaniem fotodetektorów podczerwieni o szerokim zakresie czułości spektralnej. Określono błędy systematyczne związane z wykładniczą i kątową zależnością od długości fali i współczynnika emisyjności obiektów. Przedstawiono jedną z możliwych konstrukcji pirometru do pomiaru rozgrzanych metali. Dyskutuje się również możliwość zastosowania diod laserowych o rozmiarach kwantowych oraz fotodetektorów zbudowanych w oparciu o złącza GaSb.
19
Content available remote AIII-BV(N) photodetectors with functionally graded active area
EN
Functionally graded materials (FGM) find widespread for mechanical applications. Nowadays, they become more and more attractive in fabrication of electronic and optoelectronic devices. This is due to by their unique properties. FGM are potential candidates for high sensitive photonic devices which could operate in a wide spectral range (also for voltage tunable photodetectors). In this paper, the analysis of several photodetector constructions fabricated in FGM has been presented. The influence of AIII-BV(N) grading layers composition and configuration of the detector on its optical and electrical properties has been discussed. Also, a comparison between conventional non-graded and graded devices has been made. All simulations presented in the work are performed by the specialized software designed for modeling AIII-BV(N) graded structures. The software allow us to calculate both the parameters of FGM structure and device characteristics. During the simulation process it was noticed that the bandgap gradation in phototodetector active area improved its sensitivity up to 150% compared to classical, non-graded structures. Also, another effect such the wavelength sensitivity observed in these devices makes them very attractive for applications in which the high sensitive wavelength dependence is a key factor.
PL
Omówiono nowe opracowania ITE w dziedzinie krzemowych detektorów promieniowania. W szczególności opisano unikalne detektory cząstek a, w tym 64-elementowe matryce chromatograficzne do rejestracji pojedynczych atomów pierwiastków z grupy transuranowców, opracowane we współpracy z Institut fur Radiochemie - Technische Universitat Munchen oraz dwuelementowy otwarty detektor cząstek a, opracowany we współpracy z Paul Scherrer Institut (PSI) - Villingen, Szwajcaria, do budowanego w PSI detektora COLD (Cryo-On-Une-Detector).
EN
New devices developed at the ITE in the field of silicon detectors of radiation are presented in the article. In particular, unique detectors of a particles - including 64-element, chromatographic arrays used for recording the single atoms of transuranic elements - developed in cooperation with Institut fur Radiochemie - Technische Universitat Munchen, are described, as well as a 2-element, open detector of a particles, developed in cooperation with Paul Scherrer Institut (PSI) - Villingen, Switzerland, used in the COLD detector (Cryo-On-Line-Detector) developed at PSI.
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