Wyniki wyszukiwania - BazTech

1

Two-dimensional modeling of surface photovoltage in metal/insulator/n-GaN structure with cylindrical symmetry

Matys M, Powroznik P, Powroznik P, Kupka D, Adamowicz B

Optica Applicata

|

2013

|

Vol. 43, nr 1

47--52

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.

2

Analysis of chemical shifts in Auger electron spectra versus sputtering time from passivated surfaces

Domanowska A., Adamowicz B., Bidziński P., Klimasek A., Szewczenko J., Gutt T., Przewłocki H.

Optica Applicata

|

2011

|

Vol. 41, nr 2

441--447

EN

Chemical shifts in Auger electron spectra versus Ar+ ion sputtering time were analysed for various passivated interfaces, including SiO2(100 nm)/Si, SiO2(40 nm)/4H-SiC structures and native oxide/austenitic stainless steel 316LVM. On this basis, in-depth profiles of chemical composition were determined and the thickness of passivation nanofilms was estimated. Quantitative numerical analysis was performed by means of a developed computer procedure for both the AES spectrum background subtraction and peak decomposition with pseudo-Voigt functions using evolutionary algorithms.

3

Znaczenie badań patentowych w procesie kreacji innowacji

Adamowicz B., Gonera M.

Elektronika : konstrukcje, technologie, zastosowania

|

2011

|

Vol. 52, nr 10

143-146

PL

Zdefiniowano pojęcie innowacji. Przedstawiono cykl kreacji innowacji w oparciu o model konwersji wiedzy. Omówiono znaczenie informacji patentowej w procesie innowacyjnym, w szczególności rolę badań patentowych dla inkubacji nowych pomysłów. Podano schemat ogólnej metodyki badań patentowych stanu techniki. Podkreślono znaczenie MKP dla efektywnego wyszukiwania informacji. Sformułowano postulaty upowszechnienia prowadzenia badań patentowych i ich obligatoryjności w celu zwiększenia potencjału wiedzy twórców oraz eliminacji dublowania prac badawczo-rozwojowych.

EN

Conception of innovation was defined. The cycle of innovation creation based on knowledge conversion model was presented. The role of patent information in innovation process, particularly the importance of patent research for incubation of new ideas was discussed. There was inserted the outline of patent research general methodology for technology state of art investigation. The significance of Intemational Patent Classification for effective information finding was underlined. The postulates of dissemination of patent research carrying on and its obligation for enlarging the knowledge potential of creators and elimination of research and development works doubling were formulated.

4

Profilowanie składu chemicznego tlenkowych warstw pasywacyjnych metodą spektromikroskopii elektronów Augera

Domanowska A., Klimasek A., Lisiecka E., Bidziński P., Adamowicz B., Szewczenko J., Taube A., Korwin-Mikke K., Gierałtowska S, Żywicki J.

Elektronika : konstrukcje, technologie, zastosowania

|

2011

|

Vol. 52, nr 9

63-66

PL

Zbadano rozkład zawartości pierwiastków w nanowarstwach pasywacyjnych metodą spektromikroskopii elektronów Augera w funkcji czasu trawienia jonowego (Ar⁺): (i) na powierzchni stali nierdzewnej 316L (O i Cr) oraz (ii) w struklurze HfO₂/SiO₂/SiC zawierającej buforową nanowarstwę SiO₂(Hf i Si) Do analizy widm AES wykorzystano opracowaną procedurę numeryczną, która realizuje odejmowanie tła widma oraz dekompozycję - na bazie algorytmu ewolucyjnego - nakładających się złożonych linii pierwiastków, w badanych przypadkach odpowiednio: O KLL i Cr LMM oraz Hf MNN i Si KLL Na tej podstawie wyznaczono grubość warstw tlenkowych na ok. 5-6 nm.

EN

Element content distribution in passivation nanofilms was examined using Auger electron spectromicroscopy (AES) versus ion sputtering time (Ar⁺): (i) at the 316L stainlees steel surface (O and Cr) and (ii) in the HfO₂/SiO₂/SiC structure containing SiO₂ buffer nanolayer (Hf and Si). Analysis of AES spectra was performed using an elaborated numerical procedure, which realizes the spectrum background subtraction and decomposition - using an evolutionary algorithm - of the overlapping lines in the examined cases of O KLL and Cr LMM as well as Hf MNN and Si KLL, respectively On this basis the passivation layer thickness was determined as about 5...6 nm.

5

Modelowanie zjawisk fotoelektrycznych w zakresie ultrafioletu w strukturach metal/izolator/GaN

Adamowicz B., Bidziński P., Miczek M., Matys M.

Elektronika : konstrukcje, technologie, zastosowania

|

2011

|

Vol. 52, nr 9

43-45

PL

W pracy przedstawiono teoretyczną analizę wpływu stanów elektronowych na granicy izolator/GaN oraz jakości objętości GaN (czasu życia nośników nadmiarowych) na fotopojemność i fotonapięcie powierzchniowe w spolaryzowanej elektrycznie strukturze metal/izolator/GaN oświetlonej promieniowaniem ultrafioletowym. Obliczenia wykonano korzystając z równań modelu dryftowo-dyfuzyjnego rozwiązywanych metodą elementów skończonych w pakiecie COMSOL Multiphysics. Analizę przeprowadzono pod kątem zastosowania struktury w detekcji ultrafioletu.

EN

The paper contains the theoretical analysis of the influence of electron states at an insulator/GaN mterface and of GaN bulk quality (in terms of carrier lifetime) on photocapacitance and surface photovoltage in the metal/insulator/n-GaN structure under ultraviolet light illumination and under the metal gate bias. The calculations have been done using the equations of the drift-diffusion model solved utilizing finite element method in COMSOL Multiphysics package The results have been analyzed from the viewpoint of the application of the structure for ultraviolet detection.

6

Computer analysis of oxygen adsorption at SnO2 thin films

Izydorczyk W., Adamowicz B.

Optica Applicata

|

2007

|

Vol. 37, nr 4

377-385

EN

An influence of oxidation of SnO2 thin films on depletion layer electronic parameters and film conductance has been studied by means of computer simulations. The surface potential value and in-depth potential profiles in the depletion region have been obtained by solving the Poisson--Boltzmann equation in the case of grains with slab geometry and different doping. The SnO2 grain thickness was in the range from 20 to 500 nm. The surface coverage by oxygen ions (O2-, O-) as well as film conductance per square and its sensitivity versus temperature (from 300 to 900 K) have been rigorously calculated. The effect of donor (oxygen vacancies) mobility and degree of donor ionisation has been taken into account.

7

Capacitance-voltage and Auger chemical profile studies on AlGaN/GaN structures passivated by SiO2/Si3N4 and SiNx /Si3N4 bilayers.

Adamowicz B., Miczek M., Hashizume T., Klimasek A., Żywiecki J.

Optica Applicata

|

2007

|

Vol. 37, nr 4

327-334

EN

AlGaN/GaN heterostructures passivated by SiO2/Si3N4 and SiNx/Si3N4 bilayers were characterized electrically by capacitance-voltage measurements and chemically by Auger microscopy chemical in-depth profiling. The 2-dimensional electron gas density was estimated from C-V curves and the electronic quality of the bilayers was evaluated from C-V hysteresis. Detailed variations of Auger peaks, in particular for oxygen, silicon, nitrogen, and carbon, versus argon ion sputtering time were registered. The electronic properties of these two structures were compared with each other and to their chemistry.

8

Studies of chemical composition and response of the SnO2 based sensor structure to dry and humid synthetic air

Adamowicz B., Izydorczyk W., Klimasek A., Waczyński K., Uljanow J., Jakubik W., Żywicki J.

Elektronika : konstrukcje, technologie, zastosowania

|

2006

|

Vol. 47, nr 12

5-6

EN

The measurements of the resistance response to synthetic air of the SnO₂ thin film based sensor structures were carried out. The sensing SnO₂ films were deposited on alundum substrates in the rheotaxial growth and thermal oxidation (RGTO) process. The sensor responses were registered under dry and humid airflow during structure heating and cooling (within the temperature range from 20°C to 400°C). The maximum sensor sensitivity to O₂ exposition was registered at a temperature of about 275°C. The temperature reversibility of the studied sensor response was compared with that of a commercial SnO₂ thick film Taguchi sensor. In order to understand the relationship between the sensing and chemical properties of SnO₂ films, the in-depth chemical composition profiles were investigated using the scanning Auger microprobe equipped with an Ar⁺ ion sputtering system.

PL

Zaprezentowano wyniki pomiarów rezystancji cienkich warstw sensorycznych SnO₂ otrzymanych metodą reotaksjalnego wzrostu i termicznego utleniania (RGTO). Pokazano, że wytworzone warstwy są czułe na tlen zawarty w syntetycznym powietrzu. Zarejestrowano odpowiedź sensora na suche i wilgotne syntetyczne powietrze podczas wygrzewania i ochładzania próbki (w zakresie temperatur od 20 do 400°C). Sensor wykazywał maksimum czułości na tlen zawarty w syntetycznym powietrzu w temperaturze około 275°C. Porównano temperaturową zależność odpowiedzi (przy grzaniu i chłodzeniu) badanego sensora z komercyjnym sensorem Taguchi na bazie grubych warstw SnO₂. W celu określenia zależności między właściwościami sensorowymi a składem chemicznym próbki, zbadano głębokościowe profile składu chemicznego za pomocą skaningowego mikroanalizatora elektronów Augera z systemem bombardowania jonami Ar⁺.

9

Influence of surface states and bulk traps on non-equilibrium phenomena at GaAs and GaN surfaces

Miczek M., Adamowicz B., Hashizume T., Hasegawa H.

Optica Applicata

|

2005

|

Vol. 35, nr 3

355-361

EN

The influence of surface state density Nss and bulk non-radiative lifetime t(tau) on room temperature photoluminescence quantum efficiency YPL and surface photovoltage (SPV) versus the excitation light intensity F(fi) was studied theoretically for GaAs and wurtzite GaN using self-consistent computer simulations. It was demonstrated that SPV(F) dependences are more sensitive than YPL (F) to a change in magnitude of Nss, especially for high Nss and at low F, whereas SPV is practically insensitive to t contrary to YPL. The simultaneous measurement of YPL and SPV versus , combined with rigorous computer analysis, seems to be a very promising method for contactless characterization of the surface and bulk trap parameters.

10

High-sensitivity NO2 sensor based on n-type InP epitaxial layers

Wierzbowska K., Adamowicz B., Mazet L., Brunet J., Pauly A., Bideux L., Varenne C., Berry L., Germain J. P.

Optica Applicata

|

2005

|

Vol. 35, nr 3

655-662

EN

The structure and sensing properties of a novel resistive NO2 sensor based on n-type InP epitaxial layers have been presented. The studies of sensor resistance changes due to adsorbed gas NO2 under exposures in the range from 20 to 100 ppb at a temperature of 80°C were performed. The thickness of the active InP layer changed from 0.2 to 0.4 um. The response time and signal stability were also investigated. Furthermore, the influence of surface states and near-surface region on sensor parameters in terms of the resistance relative changes was shown from numerical simulations. The analysis of the measured photoelectron spectroscopy (XPS) spectra confirmed the complex chemical composition of the InP oxides, which gives rise to the high density of surface states.

11

Komory kriogeniczne - możliwość wyboru

Adamowicz B.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

|

2005

|

Vol. 11, nr 1-2

44-46

PL

Ocena i porównanie konstrukcji i charakterystyki pracy komór kriogenicznych 2-komorowych, chłodzonych ciekłym azotem i ciekłym powietrzem syntetycznym jest problemem, którego omówienie powinno ułatwić wybór rozwiązania potencjalnym inwestorom.

12

Komory kriogeniczne - kryteria oceny

Adamowicz B., Sawicki G.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

|

2005

|

Vol. 11, nr 3-4

63-65

13

Characterization of electronic properties of InP(100) surfaces from computer-aided analysis of photoluminescence

Miczek M., Adamowicz B., Hasegawa H.

Optica Applicata

|

2002

|

Vol. 32, nr 3

226-233

EN

The surface state density distributions NSS(E) on the InP surface were determined by employing a rigorous computer analysis of the dependences of the band-to-band photoluminescence efficiency YPL versus excitation light intensity F. Experimental YPL–F spectra, taken from the literature, were obtained for the n-InP (100) surface after chemical polishing and ion bombardment. Theoretical Y PL–F curves were calculated using a numerical simulator which takes into account all bulk and surface recombination processes. The NSS(E) distributions were determined for both surfaces from the best fit to experimental data by applying a procedure based on genetic algorithm. An increase in NSS(E) after ion bombardment was attributed to the surface disordering. The behaviour of the effective surface recombination velocity and quasi-Fermi levels for electrons and for holes versus F was also analysed.

14

Determination of the surface state density distribution and fermi level position on the InP (100) surface from excitation-power-dependent photoluminescence efficiency spectra

Adamowicz B., Miczek M., Domagała T., Hasegawa H.

Elektronika : konstrukcje, technologie, zastosowania

|

2001

|

Vol. 42, nr 8-9

76-78

EN

The energy distribution of the surface state density NSS(E) on the chemically polished n-type InP (100) surface was determined from a rigorous computer analysis of the band-to-band photoluminescence efficiency (ϒ PL) versus excitation light intensity (θ). We obtained a very good modelling of the experimental ϒ PL-θ spectrum, taken from the literature, which exhibited a strong increase of ϒ PL. The theoretical values of ϒ PL were calculated using a numerical simulator taking account of all possible recombination processes in a bulk and via surface states. Due to an optimised fitting realised by means of a novel fully-computer procedure based on Genetic Algorithm, we determined the U-shaped NSS(E) distribution as well as the values of surface state cross sections for capturing electrons (σn) and holes (σp). In addition, we analysed the behaviour of the quasi-Fermi levels (EFn, EFp) on the surface and profiles of the radiative recombination velocity (Urad) under increasing excitation intensity.

15

Surface photovoltage spectroscopy system for "in situ" studies of metal phthalocyanine thin films

Bilski M., Kaszczyszyn S., Grządziel L., Adamowicz B., Szuber J.

Electron Technology

|

2000

|

Vol. 33, No. 1/2

289-29

EN

The exprimental system for in situ determination of the electronic properties of metal phthalocyanine thin films by surface photovoltage spectroscopy (SPS) is described. The preliminary results of in situ studies of the electronic properties of the space charge layer of the freshly evaporated copper phthalocyanine (CuPc) thin films are presented.

16

Computer analysis of the fermi level behaviour at SiO₂/n-Si and SiO₂/n-GaAs interfaces

Adamowicz B., Miczek M., Hesegawa H.

Electron Technology

|

2000

|

Vol. 33, No. 1/2

249-252

EN

A theoretical analysis of the interface Fermi level positipon (EFS) and band bending (qVs) at SiO₂/n-Si and SiO₂/n-GaAs interfaces, with different interface state density and fixed charge, has been performed for modelling and analysis of metal-insulator-semiconductor (MIS) structure-based ion and gas sensors. A U-shaped interface state continuum has been assumed in accordance with the Disorder Induced Gap State model. From the calculated dependencies of the interface Fermi level position versus the minimum interface state density (NSSO), the ranges of EFS free movement and its pinning position in energy gap have been found. Furthermore, an influencedetermined, indicating remarkable charge detection sensitivity and dynamic ranges.