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1

On the Validity of Diffusional Model in Determination of Electric Transport Parameters of Semiconductor Compound

100%

Dussan A., Mesa F.

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vol. 125

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issue 2

171-173

EN

In this work we have studied the variable range hopping as a predominant electronic transport mechanism for semiconductor materials used as absorbent layer in photovoltaic devices. Dark conductivity measurements were carried out from 120 to 420 K in Si, Cu_3BiS_3, SnS, Cu_2ZnSnSe_4, and CuInGaSe_2 thin films. In the low-temperature range, variational range hopping was established for all samples. Using classical equations from the percolation theory and the diffusional model, the density of states near the Fermi level (N_{F}), as well as the hopping parameters (W - activation energy and R - hopping range) were calculated. A correlation between both models allowed us to evaluate the validity of the diffusional model in semiconductor compounds.

2

Growth Analysis and Numerical Simulation of Cu_3BiS_3 Absorbing Layer Solar Cell through the wxAMPS and Finite Element Method

81%

Mesa F., Ballesteros V., Dussan A.

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vol. 125

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issue 2

385-387

EN

The properties and the efficiency of a semiconductor thin film depend on the state of stress and defects in the film structure. When the film is growing layer by layer, the elastic energy due to deformation stress between the substrate and the film is released partly due to the formation of dislocations in the critical thickness deformation. In this paper, we present a finite element analysis of the stress state in a thin film of Cu_3BiS_3 as a function of thickness and elastic energy release by nucleation of dislocations. Initially, we analyze the stress contours associated with the epitaxial growth and dislocation nucleation and then combine these two in order to study the effective potential energy state of the system. Finally, the tool wxAMPS is today an important application for simulation of solar cells with high reliability and an improved design over its analysis of microelectronic and photonic structures predecessor, incorporating physical principles concerning photovoltaic phenomena and uses a new method for solving algorithms, combining Newton and Gummel approaches, which provides greater stability and speed of computation.

3

Density of States in Thin Boron-Doped Microcrystalline Silicon Films Estimated from the Thermally Stimulated Conductivity Method

81%

Dussan A., Schmidt J., Koropecki R.

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vol. 125

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issue 2

174-176

EN

In this work, a series of boron-doped microcrystalline silicon samples [μc-Si:H(B)] were deposited by plasma-enhanced chemical vapor deposition, using silane (SiH_4) diluted in hydrogen, and diborane (B_2H_6) as a dopant gas. The concentration of B_2H_6 in SiH_4 was varied in the range of 0-100 ppm. The density of states was obtained from the thermally stimulated conductivity technique and compared with results obtained by the modulated photoconductivity methods. To explain the poor agreement between the density of states obtained from the thermally stimulated conductivity and the other methods, it is shown by means of numerical simulations that the density of states is very sensitive to experimental errors introduced in the calculation of the μ_{n}τ_{n} product (mobility of electron × lifetime of the electron). The thermally stimulated conductivity method is applied here for the first time to calculate the density of defect states in the forbidden band of μc-Si:H samples.

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3 Acta Physica Polonica A

3 2014

3 Dussan A.

2 Mesa F.

1 Ballesteros V.

1 Koropecki R.

1 Schmidt J.

On the Validity of Diffusional Model in Determination of Electric Transport Parameters of Semiconductor Compound

Growth Analysis and Numerical Simulation of Cu_3BiS_3 Absorbing Layer Solar Cell through the wxAMPS and Finite Element Method

Density of States in Thin Boron-Doped Microcrystalline Silicon Films Estimated from the Thermally Stimulated Conductivity Method