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Germanium and tin nanoparticles encapsulated in amorphous silicon matrix for optoelectronic application
Stuchlíková, The-Ha; Remeš, Zdeněk; Stuchlík, Jiří
2019 - anglický
The plasma enhanced chemical vapour deposition was combined with in situ deposition of Ge and Sn thin film by evaporation technique at surface temperature about 220 °C to form nanoparticles on the surface of hydrogenated silicon thin films to prepare diodes. Formation of nanoparticles was additionally stimulated by plasma treatment through a low pressure hydrogen glow discharge. The diodes based on PIN diode structures with and without the embedded Ge or Sn nanoparticles were characterized by temperature dependence of electrical conductivity, activation energy of conductivity, measurement of volt-ampere characteristics in dark and under solar illumination\n
Klíčová slova:
Ge NPs; a-Si:H; Sn NPs; diode structures; I-V characteristics
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Germanium and tin nanoparticles encapsulated in amorphous silicon matrix for optoelectronic application
The plasma enhanced chemical vapour deposition was combined with in situ deposition of Ge and Sn thin film by evaporation technique at surface temperature about 220 °C to form nanoparticles on the ...
The hydrogen plasma doping of ZnO thin films and nanoparticles
Remeš, Zdeněk; Neykova, Neda; Potocký, Štěpán; Chang, Yu-Ying; Hsu, H.S.
2018 - anglický
The optical absorptance and photoluminescence studies has been applied on the hydrogen and oxygen plasma treated, nominally undoped ZnO thin films and aligned nanocolumns grown on the nucleated glass substrate by the hydrothermal process in an oil bath containing a flask with ZnO nutrient solution. The localized defect states at 2.3 eV below the optical absorption edge were detected by photothermal deflection spectroscopy (PDS) in a broad spectral range from near UV to near IR. The optical absorptance spectroscopy shows that hydrogen doping increases free electron concentration changing ZnO to be electrically conductive (hydrogen doping).\n
Klíčová slova:
ZnO; nanoparticles; hydrothermal growth; hotoluminescence spectroscopy; PDS
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
The hydrogen plasma doping of ZnO thin films and nanoparticles
The optical absorptance and photoluminescence studies has been applied on the hydrogen and oxygen plasma treated, nominally undoped ZnO thin films and aligned nanocolumns grown on the nucleated glass ...
Studium cesno-hafničitého chloridu metodami termické analýzy
Král, Robert; Zemenová, Petra; Bystřický, Aleš; Vaněček, Vojtěch; Kohoutková, M.
2018 - český
Tato práce se zabývá studiem procesů probíhajících při tepelném zatížení připraveného chloridu cesno-hafničitého (Cs2HfCl6) a jeho monokrystalu metodami termické analýzy: simultánní diferenciální skenovací kalorimetrií a termogravimetrií (DSC-TG) a termomechanickou analýzou (TMA). Výsledky prokázaly tepelnou nestabilitu Cs2HfCl6 a jeho rozklad na chlorid cesný a hafničitý nad eutektickou teplotou.\n This work deals with the study of processes in cesium hafnium chloride (Cs2HfCl6) and its single crystal under thermal treatment by thermal analyses (different scanning calorimetry, thermogravimetry and thermomechanical analysis). Results showed thermal instability of Cs2HfCl6 and its significant decomposition to cesium and hafnium chloride above the eutectic temperature.
Klíčová slova:
Cs.sub.2./sub.HfCl.sub.6./sub.; DSC-TG; TMA; krystal
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Studium cesno-hafničitého chloridu metodami termické analýzy
Tato práce se zabývá studiem procesů probíhajících při tepelném zatížení připraveného chloridu cesno-hafničitého (Cs2HfCl6) a jeho monokrystalu metodami termické analýzy: simultánní diferenciální ...
Modeling of monocrystalline magnesium microbeam bending
Němeček, J.; Maňák, Jan; Němeček, J.
2018 - anglický
This paper presents a numerical simulation of a micro-scale experiment on a magnesium alloy. Three dimensional numerical FE model with elastoplastic behavior respecting crystal anisotropy was used to fit experimental load displacement curves.
Klíčová slova:
magnesium; microbeams; crystal anisotropy; FE model
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Modeling of monocrystalline magnesium microbeam bending
This paper presents a numerical simulation of a micro-scale experiment on a magnesium alloy. Three dimensional numerical FE model with elastoplastic behavior respecting crystal anisotropy was used to ...
Characterization of hydrogenated silicon thin films and diode structures with integrated germanium nanoparticles
Stuchlík, Jiří; Fajgar, Radek; Kupčík, Jaroslav; Remeš, Zdeněk; Stuchlíková, The-Ha
2018 - anglický
Substrates with ZnO (or ITO) conductive layers were covered by thin film of a-Si:H deposited by PECVD technique. Under a turbo-molecular vacuum (10-4 Pa) the reactive laser ablation (RLA) was used to cover this a-Si:H thin film by germanium NPs. The RLA was performed using focused excimer ArF laser beam (193 nm, 100 mJ/pulse) under SiH4 background atmosphere (0.5 Pa). As a target the elemental germanium was used. Reaction between ablated Ge and silane led to formation of Ge NPs covered by thin SiGe layer. Then the deposited NPs were covered and stabilized by a-Si:H layer by PECVD. Those two deposition processes was alternated and applied a few times. The Si:H thin films with integrated Ge NPs were characterized by microscopic, spectroscopic and diffraction techniques. I-V characteristics of final diode structures without and under illumination were measured as well as their electroluminescence behaviour.
Klíčová slova:
PECVD; a-Si:H diode structures; Ge; nanoparticles
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Characterization of hydrogenated silicon thin films and diode structures with integrated germanium nanoparticles
Substrates with ZnO (or ITO) conductive layers were covered by thin film of a-Si:H deposited by PECVD technique. Under a turbo-molecular vacuum (10-4 Pa) the reactive laser ablation (RLA) was used to ...
Characterization of hydrogenated silicon thin films and diode structures with integrated silicon and germanium nanoparticles
Stuchlík, Jiří; Fajgar, R.; Remeš, Zdeněk; Kupčík, Jaroslav; Stuchlíková, Hana
2018 - anglický
P-I-N diode structures based on the thin films of amorphous hydrogenated silicon (a-Si:H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique were prepared with embedded Si and Ge nanoparticles. The Reactive Laser Ablation (RLA) of germanium target was used to cover the intrinsic a-Si:H layer by Ge NPs under a low pressure of the silane. The RLA was performed using focused excimer ArF laser beam under SiH4 background atmosphere. Reaction between ablated Ge NPs and SiH4 led to formation of Ge NPs covered by thin GeSi:H layer. The deposited NPs were covered and stabilized by a-Si:H layer by PECVD. Those two deposition processes were alternated repeatedly. Volt-ampere characteristics of final diode structures were measured in dark and under illumination as well as their electroluminescence spectra.
Klíčová slova:
a-Si:H; PIN diode; thin films; reactive laser ablation; nanoparticles
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Characterization of hydrogenated silicon thin films and diode structures with integrated silicon and germanium nanoparticles
P-I-N diode structures based on the thin films of amorphous hydrogenated silicon (a-Si:H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique were prepared with embedded Si and Ge ...
Histology and micro-CT study of diamond-coated metal bone implants in rabbit femurs
Potocký, Štěpán; Ižák, Tibor; Dragounová, Kateřina; Kromka, Alexander; Rezek, Bohuslav; Mandys, V.; Bartoš, M.; Bačáková, Lucie; Sedmera, David
2018 - anglický
A conformal coating of a thin diamond layer on three-dimensional metal bone implants was shown directly on stainless steel and TiAl6V4 cortical screw implant using ultrasonic and composite polymer pretreatment method. The best conformation coverage was achieved in the case of the WO3 interlayer for both stainless steel and TiAl6V4 screws. The process of osteointegration of the screw implants into rabbit femurs is evidenced by the formation of a bone edge via desmogenous ossification around the screws in less than six months after implantation. A detailed evaluation of the tissue reaction around the implanted screws shows good biocompatibility of diamond-coated metal bone implants.
Klíčová slova:
screw implant; diamond coating; osteointegration; histology
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Histology and micro-CT study of diamond-coated metal bone implants in rabbit femurs
A conformal coating of a thin diamond layer on three-dimensional metal bone implants was shown directly on stainless steel and TiAl6V4 cortical screw implant using ultrasonic and composite polymer ...
Electronic transfer between nanostructures. Negative differential resistance in conductive polymers.
Král, Karel; Menšík, Miroslav
2018 - anglický
The effect of negative differential resistance can be observed experimentally in some material systems based on polymers. These observation are explained usually to be due to the presence of certain carrier traps which can capture the carriers of the electric current. In the present theoretical work we are going to show that besides this carrier trapping origin of the negative differential resistance there can also be an intrinsic mechanism present, causing such an effect. Namely, instead of the traps, the electron-phonon interaction can cooperate with the tunneling of the charge carriers between their localized states and can provide the effect the negative differential resistance. This electron-phonon interaction is included in a non-perturbative way. The theory will be briefly summarized and explained.
Klíčová slova:
electronic transfer; charge transfer; nanostructures; quantum dots; nonequilibrium transport theory
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Electronic transfer between nanostructures. Negative differential resistance in conductive polymers.
The effect of negative differential resistance can be observed experimentally in some material systems based on polymers. These observation are explained usually to be due to the presence of certain ...
Mechanical properties of Cr-DLC layers prepared by hybrid laser technology
Písařík, Petr; Jelínek, Miroslav; Remsa, J.; Tolde, Z.
2017 - anglický
Diamond like carbon (DLC) layers have excellent biological properties for use in medicine for coating implants, but poor adhesion to biomedical alloys (titanium alloys, chromium alloys and stainless steel). The adhesion can be improved by doping the DLC layer by chromium, as described in this article. Chromium doped diamond like carbon layers (Cr DLC) were deposited by hybrid deposition system using KrF excimer laser (deposition diamond like carbon - graphite target) and\nmagnetron sputtering (deposition chromium - chromium target). Carbon and chromium contents were determined by wavelength dispersive X-ray spectroscopy.\n
Klíčová slova:
DLC; chromium doped; mechanical properties; PLD
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Mechanical properties of Cr-DLC layers prepared by hybrid laser technology
Diamond like carbon (DLC) layers have excellent biological properties for use in medicine for coating implants, but poor adhesion to biomedical alloys (titanium alloys, chromium alloys and stainless ...
Correlated microscopy of electronic and material properties of graphene grown on diamond thin films
Rezek, Bohuslav; Čermák, Jan; Varga, Marián; Tulic, S.; Skákalová, V.; Waitz, T.; Kromka, Alexander
2017 - anglický
In this work we compare growth of graphene on diamond thin films that enable large area processing. We use films with different crystal size and surface roughness to obtain deeper insight into formation and properties of GoD. The diamond films are coated by a nm thin sputtered Ni layer and heated to 900°C in a forming gas atmosphere (H2/Ar) to initiate catalytic thermal CVD process. The samples are cleaned from residual Ni after the growth process. We employ scanning electron microscopy, Raman micro-spectroscopy and Kelvin probe force microscopy to correlate material, structural, and electronic properties of graphene on diamond. We show how grain size and grain boundaries influence graphene growth and material and electronic properties. For instance we show that the grain boundaries (with non-diamond carbon phases) in diamond films have an important role. They influence the electronic properties and they are beneficial for forming graphene on diamond higher quality.
Klíčová slova:
graphene; diamond; microscopy; micro-spectroscopy; electronic properties
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Correlated microscopy of electronic and material properties of graphene grown on diamond thin films
In this work we compare growth of graphene on diamond thin films that enable large area processing. We use films with different crystal size and surface roughness to obtain deeper insight into ...
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