A model of electrical conduction in polycrystalline silicon

Joshi, D. P.; Srivastava, R. S.

doi:10.1109/t-ed.1984.21631

Cited by 44 publications

(18 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The physical mechanisms for these changes in the transport properties of polycrystalline materials have been the subject of much discussion, especially for polycrystalline silicon. 31,32 The reduction in the lattice thermal conductivity is attributed to strong interface scattering of phonons. 2 For charge carriers, the generally accepted model to explain the effects of grain boundaries is the charge-trapping model.…”

Section: Modeling Nanocompositesmentioning

confidence: 99%

“…Many other models for grain-boundary scattering in polycrystalline materials attempt to obtain I-V characteristics by considering thermionic field-emission and tunneling processes. [31][32][33][34] However, this framework neglects the energy relaxation of charge carriers and can result in unrealistically large Seebeck coefficients, especially in nanocomposites. For this reason, we focus on calculating grain-boundary scattering rates, allowing all the properties to be determined in a self-consistent manner.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling study of thermoelectric SiGe nanocomposites

et al. 2009

View full text Add to dashboard Cite

Nanocomposite thermoelectric materials have attracted much attention recently due to experimental demonstrations of improved thermoelectric properties over those of the corresponding bulk material. In order to better understand the reported data and to gain insight into transport in nanocomposites, we use the Boltzmann transport equation under the relaxation-time approximation to calculate the thermoelectric properties of n-type and p-type SiGe nanocomposites. We account for the strong grain-boundary scattering mechanism in nanocomposites using phonon and electron grain-boundary scattering models. The results from this analysis are in excellent agreement with recently reported measurements for the n-type nanocomposite but the experimental Seebeck coefficient for the p-type nanocomposite is approximately 25% higher than the model's prediction. The reason for this discrepancy is not clear at the present time and warrants further investigation. Using new mobility measurements and the model, we find that dopant precipitation is an important process in both n-type and p-type nanocomposites, in contrast to bulk SiGe, where dopant precipitation is most significant only in n-type materials. The model also shows that the potential barrier at the grain boundary required to explain the data is several times larger than the value estimated using the Poisson equation, indicating the presence of crystal defects in the material. This suggests that an improvement in mobility is possible by reducing the number of defects or reducing the number of trapping states at the grain boundaries.

show abstract

Section: Modeling Nanocompositesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modeling study of thermoelectric SiGe nanocomposites

et al. 2009

View full text Add to dashboard Cite

show abstract

“…3 At intermediate temperatures, besides the thermionic emission, carriers tunnel through the barrier after being thermally emitted over the barrier potential caused by the trapped charge. [3][4][5] The tunneling can be interpreted as an impeding factor of the thermionic emission. In fact, the dominant portion in the tunneling current is given by…”

Section: ͑4͒mentioning

confidence: 99%

“…4,5 Temperature dependence of the factors before the exponential is weak compared with the exponential. Equation ͑5͒…”

Section: ͑5͒mentioning

confidence: 99%

Evaluation of grain boundary trap states in polycrystalline–silicon thin-film transistors by mobility and capacitance measurements

Ikeda¹

2002

Journal of Applied Physics

View full text Add to dashboard Cite

A method for evaluating localized grain boundary (GB) trap states in polycrystalline–silicon thin-film transistors (poly-Si TFTs) is proposed. Field effects in poly-Si TFTs are analyzed by decomposition of the two-dimensional Poisson’s equation. This analysis gives the theoretical basis for evaluating the localized GB trap state density. The trap states are evaluated with the GB barrier potential given by the activation energy of the effective mobility and with the surface potential calculated from the capacitance–voltage characteristics in poly-Si TFTs. This evaluating method was applied to several different types of poly-Si TFTs fabricated with excimer laser annealing crystallization processes. This method has succeeded experimentally in eliminating the error effects related to oxide–semiconductor interface trap states and in clarifying that the GB barrier potential has a peak in its gate bias dependence. This method has also elucidated that the GB trap state density has almost the same value independent of the grain size when the hydrogenation efficiency in poly-Si is in the same level between TFTs. The good agreement of the simulated and the measured drain currents confirm the validity of this method.

show abstract

“…6 On the other hand, the potential barrier at the grain boundary level expresses that the grain boundary behaves as an intrinsic wide-band-gap semiconductor, the gap of which is different from that of silicon. 18 Thus, polysilicon resistivity poly can be expressed by a neutral region and a potential barrier contribution, as follows:…”

Section: Piezoresistivity Of Polycrystalline Siliconmentioning

confidence: 99%

Stress-dependent hole effective masses and piezoresistive properties ofp-type monocrystalline and polycrystalline silicon

et al. 1998

View full text Add to dashboard Cite

Piezoresistive effects of p-type polycrystalline silicon underline that longitudinal and transversal piezoresistive properties in monocrystalline silicon do not have the same physical origin, which is not accounted for in current models. This difference is highlighted by the study of the mechanical stress effect on the valence band, which shows that piezoresistive properties of p-type monocrystalline silicon can be explained in terms of both hole transfer between heavy-and light-hole valence bands and stress-dependent hole effective masses. The quantification of these phenomena points out that longitudinal piezoresistive properties are mainly due to the hole transfer, whereas transversal ones are mainly attributed to the effective mass change effects. This enables one to model p-type polycrystalline silicon piezoresistivity, in particular the sign change of the transversal gauge factor at high doping level. ͓S0163-1829͑98͒01615-4͔

show abstract

A model of electrical conduction in polycrystalline silicon

Cited by 44 publications

References 16 publications

Modeling study of thermoelectric SiGe nanocomposites

Modeling study of thermoelectric SiGe nanocomposites

Evaluation of grain boundary trap states in polycrystalline–silicon thin-film transistors by mobility and capacitance measurements

Stress-dependent hole effective masses and piezoresistive properties ofp-type monocrystalline and polycrystalline silicon

Contact Info

Product

Resources

About