Numerical investigation of a double-junction a:Si Ge thin-film solar cell including the multi-trench region

We present a new approach based on the multi-trench technique to improve the electrical performances, which are the fill factor and the electrical efficiency. The key idea behind this approach is to introduce a new multi-trench region in the intrinsic layer, in order to modulate the total resistance of the solar cell. Based on 2- D numerical investigation and optimization of amorphous SiGe double-junction （a-Si：H/a-SiGe：H） thin film solar cells, in the present paper numerical models of electrical and optical parameters are developed to explain the impact of the multi-trench technique on the improvement of the double-junction solar cell electrical behavior for high performance photovoltaic applications. In this context, electrical characteristics of the proposed design are analyzed and compared with conventional amorphous silicon double-junction thin-film solar cells.

An optimized junctionless GAA MOSFET design based on multi-objective computation for high-performance ultra-low power devices

An analytical investigation has been proposed to study the subthreshold behavior ofjunctionless gates all around （JLGAA） MOSFET for nanoscale CMOS analog applications. Based on 2-D analytical analysis, a new subthreshold swing model for short-channel JLGAA MOSFETs is developed. The analysis has been used to calculate the subthreshold swing and to compare the performance of the investigated design and conventional GAA MOSFET, where the comparison of device architectures shows that the JLGAA MOSFET exhibits a superior performance with respect to the conventional inversion-mode GAA MOSFET in terms of the fabrication process and electrical behavior in the subthreshold domain. The analytical models have been validated by 2-D numerical simulations. The proposed analytical models are used to formulate the objectives functions. The overall objective function is formulated by means of a weighted sum approach to search the optimal electrical and dimensional device parameters in order to obtain the better scaling capability and the electrical performance of the device for ultra-low power applications.

A fuzzy-logic-based approach to accurate modeling of a double gate MOSFET for nanoelectronic circuit design

The double gate （DG） silicon MOSFET with an extremely short-channel length has the appropriate fea- tures to constitute the devices for nanoscale circuit design. To develop a physical model for extremely scaled DG MOSFETs, the drain current in the channel must be accurately determined under the application of drain and gate voltages. However, modeling the transport mechanism for the nanoscale structures requires the use of overkill meth- ods and models in terms of their complexity and computation time （self-consistent, quantum computations ）. Therefore, new methods and techniques are required to overcome these constraints. In this paper, a new approach based on the fuzzy logic computation is proposed to investigate nanoscale DG MOSFETs. The proposed approach has been implemented in a device simulator to show the impact of the proposed approach on the nanoelectronic cir- cuit design. The approach is general and thus is suitable for any type ofnanoscale structure investigation problems in the nanotechnology industry.

A compact charge-based model to study the nanoscale undoped double gate MOSFETs for nanoelectronic circuit design using genetic algorithms

The analytical modeling of nanoscale devices is an important area of computer-aided design for fast and accurate nanoelectronic design and optimization. In the present paper, a new approach for modeling semicon- ductor devices, nanoscale double gate DG MOSFETs, by use of the gradual channel approximation （GC） approach and genetic algorithm optimization technique （GA） is presented. The proposed approach combines the universal optimization and fitting capability of GA and the cost-effective optimization concept of quantum correction, to achieve reliable, accurate and simple compact models for nanoelectronic circuit simulations. Our compact models give good predictions of the quantum capacitance, threshold voltage shift, quantum inversion charge density and drain current. These models have been verified with 2D self-consistent results from numerical calculations of the coupled Poisson-Schrrdinger equations. The developed models can also be incorporated into nanoelectronic cir- cuit simulators to study the nanoscale CMOS-based devices without impact on the computational time and data storage.

ANFIS-based approach to studying subthreshold behavior including the traps effect for nanoscale thin-film DG MOSFETs

A fuzzy framework based on an adaptive network fuzzy inference system（ANFIS） is proposed to evaluate the relative degradation of the basic subthreshold parameters due to hot-carrier effects for nanoscale thin-film double-gate（DG） MOSFETs.The effect of the channel length and thickness on the resulting degradation is addressed, and 2-D numerical simulations are used for the elaboration of the training database.Several membership function shapes are developed,and the best one in terms of accuracy is selected.The predicted results agree well with the 2-D numerical simulations and can be efficiently used to investigate the impact of the interface fixed charges and quantum confinement on nanoscale DG MOSFET subthreshold behavior.Therefore,the proposed ANFIS-based approach offers a simple and accurate technique to study nanoscale devices,including the hot-carrier and quantum effects.