Wyniki wyszukiwania - Biblioteka Nauki

1

Changes in the Activation Energy of Radiation Defects in Strongly Defected Silicon Depending on the Type and Concentration of Dopant

100%

Węgierek P. , Billewicz P.

Acta Physica Polonica A

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2014

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tom 125

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nr 6

1392-1396

EN

The article presents the outcome of the research on alternating-current electric conduction in silicon doped with boron, phosphorus, and antimony of resistivities ρ=0.01 Ω cm and ρ=10 Ω cm, strongly defected by the implantation of Ne^{+} ions (D=1.5 × 10^{14} cm^{-2}, E=100 keV). On the basis of results obtained for samples annealed at the temperature T_{a}=598 K and measured at the testing temperature T_{p}=298 K and frequency f=1 MHz it was possible to carry out an analysis of mechanisms of electric conduction depending on the type and concentration of dopant. Obtained results confirmed the occurrence of hopping conductivity mechanism in strongly defected semiconductors, which is typical for high frequency values.

2

Influence of Temperature on Electrical Parameters of GaAs in the Aspect of Applications in Photovoltaics

100%

Węgierek P. , Billewicz P.

Acta Physica Polonica A

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2015

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tom 128

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nr 5

875-878

EN

The article describes the results of the research on thermal stability of electrical parameters of n-type gallium arsenide doped with tellurium, defected by ion implantation, measured at the operating temperature ranging from 77 K to 373 K. The aim of the work is to investigate the character of changes in the values of such electrical parameters as resistivity, capacity and loss tangent of the tested GaAs samples, exposed to different thermal conditions. Temperature dependences analyzed in the paper could be taken as a basis to formulate general speculations concerning potential applications of the tested material as a substrate in the process of photovoltaic cells production. The phenomenon of conversion of solar energy into electricity is strongly connected with electrical properties of photovoltaic cell substrate material and its internal structure. Moreover, the efficiency of photoconversion is affected by such factors as charge carrier lifetime distribution and diffusion length in the base material. Therefore, it is necessary to confirm what is the character of the influence of operating temperature on the electrical parameters of GaAs and what modification could be introduced in the material in order to increase the efficiency of photoconversion.

3

Research on Thermal Stability of Electrical Parameters of Silicon Used in PV Cells Production Process

100%

Węgierek P. , Billewicz P.

Acta Physica Polonica A

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2015

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tom 128

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nr 5

943-945

EN

Considering the results of recent research, it is possible to state that the problem of thermal stability of electrical parameters of silicon is very important in the context of efficiency of commonly used photovoltaic cells. Subsequent investigations confirmed that the efficiency of photovoltaic cells is strongly influenced by active defects of silicon crystal lattice. Those defects, arising in the process of photovoltaic cells base material preparation, are responsible for changes in the values of conductivity and activation energy of the tested material. Taking this into consideration, it is reasonable to carry out research oriented at experimental verification of the influence of both operating temperature on the electrical parameters of silicon and annealing temperature on the distribution of radiation defects in the silicon substrate used in the production of photovoltaic cells. The main purpose of this work is a comparative analysis of dependences of electrical parameters of silicon on temperature. The article presents the results of the research on resistivity and capacity of silicon samples (doped with boron and phosphorus) whose structure was modified by the ion implantation process.

4

Research on Mechanisms of Electric Conduction in the p-Type Silicon Implanted with Ne^{+} Ions

100%

Węgierek P. , Billewicz P.

Acta Physica Polonica A

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2013

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tom 123

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nr 5

948-951

EN

The article presents the results of research on alternating-current electric conduction in boron-doped silicon (ρ = 10 Ω cm), strongly defected by the implantation of Ne^{+} ions (D = 1.5 × 10^{14} cm^{-2}, E = 100 keV). The analysis of changes in electrical characteristics recorded at the sample annealing temperature of T_{a} = 373 K has been presented, concerning the influence of the testing temperature ranging from 253 K to 368 K as well as the frequency from 50 Hz to 5 MHz. The obtained results have confirmed the occurrence of two electric conduction mechanisms in strongly defected semiconductors, such as the band conduction mechanism that is characteristic of low frequency values and the jump conduction one that corresponds to higher frequencies.

5

Application of Ion Implantation for Intermediate Energy Levels Formation in the Silicon-Based Structures Dedicated for Photovoltaic Purposes

80%

Billewicz P. , Węgierek P. , Grudniewski T. , Turek M.

Acta Physica Polonica A

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2017

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tom 132

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nr 2

274-277

EN

The main aim of the research was to verify if it is possible to create the intermediate energy levels in silicon by means of ion implantation as well as to confirm whether the intermediate band could arise. The tests covered recording of conductance and capacitance of antimony-doped silicon, implanted with Ne⁺ ions. As a result, it was possible to identify a single deep level in the sample and determine its location in the band gap by estimating the value of activation energy.

6

Formation of Noncoil-Like Inductance in Nanocomposites (Fe_{0.45}Co_{0.45}Zr_{0.10})_{x}(Al_2O_3)_{1-x} Manufactured by Ion-Beam Sputtering of Complex Targets in Ar+O_2 Atmosphere

61%

Zhukowski P. , Kołtunowicz T. , Węgierek P. , Fedotova J. , Fedotov A. , Larkin A.

Acta Physica Polonica A

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2011

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tom 120

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nr 1

43-45

EN

This paper investigates the inductive contribution to AC conductance in the granular nanocomposites (Fe_{0.45}Co_{0.45}Zr_{0.10})_{x}(Al_2O_3)_{1-x}. The initial nanocomposites studied were manufactured in Ar+O_2 atmosphere by ion-beam sputtering of the target containing Fe_{0.45}Co_{0.45}Zr_{0.10} and alumina stripes and then subjected to the annealing procedure in air over the temperature range 373 K < T_{a} < 873 K. These samples, before and after annealing, were studied using the temperature 77 K < T_{p} < 300 K and frequency 50 Hz < f < 1 MHz dependences of a real part of the admittance σ(T, f). Analysis of the observed σ (f, T_{p}) dependences for x < 0.5 demonstrated that in the studied samples the equivalent circuits with the capacitive and noncoil-like inductive contributions can be accomplished. Just in this case, the capacitive properties of RLC circuit with the phase angle - 90° ≤ θ_{L} < 0° are exhibited at low frequencies and the inductive properties with 0° ≤ θ_{H} < 90° become apparent at high frequencies. A value of the critical frequency f_{R}, where θ_{H} changes sign, depends on the metallic phase concentration x, measuring temperature T_{p}, and annealing temperature T_{a}.

7

Production of Molybdenum and Tantalum Ion Beams using CCl₂F₂

51%

Turek M. , Droździel A. , Pyszniak K. , Filiks J. , Prucnal S. , Mączka D. , Vaganov Y. , Węgierek P.

Acta Physica Polonica A

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2017

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tom 132

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nr 2

283-287

EN

A new method of refractory metal (like Mo and Ta) ion beam production using the arc discharge ion source and CCl₂F₂ (dichlorodifluoromethane) used as a feeding gas supported into the discharge chamber is presented. It is based on etching of the refractory metal parts (e.g. anode or a dedicated tube) Cl and F containing plasma. The results of measurements of the dependences of ion currents on the working parameters like discharge and filament currents as well as on the magnetic field flux density of an external electromagnet coil are shown and discussed. The separated Mo⁺ and Ta⁺ beam currents of approximately 22 μA and 2 μA, respectively, were obtained.