The efficiency improvements achieved by adding idealized, top-mounted, down-conversion (DC) and luminescent down-shifting (LDS) layers to a commercial grade silicon solar cell are studied. A comparison is then made to silicon nanocrystals... more
The efficiency improvements achieved by adding idealized, top-mounted, down-conversion (DC) and luminescent down-shifting (LDS) layers to a commercial grade silicon solar cell are studied. A comparison is then made to silicon nanocrystals (Si-NC) LDS layer coupled to a silicon solar cell, where the optical properties of the Si-NC are based on measured data. Since the modeled DC and LDS layers are electrically isolated from the solar cell, the devices are studied by modifying the incident AM1.5G spectrum according to the bandgap, absorption and emission profiles, and global efficiency of the DC and LDS layers. Simulation results indicate that a minimum DC/LDS efficiency of 1% is required to enhance the solar cell efficiency, and that this threshold rises to 38% for a Si-NC based LDS layer. Additionally, the incorporation of an optimal, perfectly efficient DC layer (200%) is shown to enhance the photovoltaic efficiency from 14.1% to 16.6% as opposed to
16.3% for a perfect LDS layer (100%).
—In this paper we present a numerical analysis of Schottky Barrier Diodes (SBDs) based on CVD (Chemical Vapour Deposition) Diamond. Material and interface models suitable for TCAD (Technology Computer Aided Design) finite element... more
—In this paper we present a numerical analysis of Schottky Barrier Diodes (SBDs) based on CVD (Chemical Vapour Deposition) Diamond. Material and interface models suitable for TCAD (Technology Computer Aided Design) finite element simulations were implemented in the software and their validity was assessed against experimental results obtained on MIP + (Metal-Intrinsic layer-highly P doped substrate) SBDs with Al and Au as Schottky metal contacts both at room and higher temperature conditions. The paper also highlights the need to improve such TCAD models since the complex behavior of Diamond based devices is still not well captured in static and dynamic conditions. The present work also discusses the role of the Oxygen surface interface in the on state performances of the SBDs.
In this paper we present the design criteria of Lightly Doped Drain (LDD) MOSFETs through the study of the influence of the n-doping of drain/source on the electric field, but taking into account also the impact of LDD on series... more
In this paper we present the design criteria of Lightly Doped Drain (LDD) MOSFETs through the study of the influence of the n-doping of drain/source on the electric field, but taking into account also the impact of LDD on series resistance of the device and the channel length contribution on breakdown voltage reduction.
A double-lateral-gate p-type junctionless transistor is fabricated on a low-doped (10(15)) silicon-on-insulator wafer by a lithography technique based on scanning probe microscopy and two steps of wet chemical etching. The experimental... more
A double-lateral-gate p-type junctionless transistor is fabricated on a low-doped (10(15)) silicon-on-insulator wafer by a lithography technique based on scanning probe microscopy and two steps of wet chemical etching. The experimental transfer characteristics are obtained and compared with the numerical characteristics of the device. The simulation results are used to investigate the pinch-off mechanism, from the flat band to the off state. The study is based on the variation of the carrier density and the electric-field components. The device is a pinch-off transistor, which is normally in the on state and is driven into the off state by the application of a positive gate voltage. We demonstrate that the depletion starts from the bottom corner of the channel facing the gates and expands toward the center and top of the channel. Redistribution of the carriers due to the electric field emanating from the gates creates an electric field perpendicular to the current, toward the bottom...
The performance effects of silicon nanocrystals (SiNC) embedded in a silicon dioxide matrix to act as a down-shifting (DS) layer mounted on the top surface of a polycrystalline Cu(In,Ga)Se2 solar cell are explored numerically. The DS... more
The performance effects of silicon nanocrystals (SiNC) embedded in a silicon dioxide matrix to act as a down-shifting (DS) layer mounted on the top surface of a polycrystalline Cu(In,Ga)Se2 solar cell are explored numerically. The DS layers are modeled by modifying the incident AM1.5G spectrum based on the absorption and emission properties of the SiNC. The effects of the DS layers as an anti-reflection coating leads to an 11.4% relative improvement in short-circuit current density under 1-sun illumination (0.1 W/cm2). Comparatively, the effect of down-shifting high-energy photons to lower energy photons showed a 4% relative short-circuit current density improvement, albeit for an optical conversion efficiency of 80%.
A double-lateral-gate p-type junctionless transistor is fabricated on a low-doped (10(15)) silicon-on-insulator wafer by a lithography technique based on scanning probe microscopy and two steps of wet chemical etching. The experimental... more
A double-lateral-gate p-type junctionless transistor is fabricated on a low-doped (10(15)) silicon-on-insulator wafer by a lithography technique based on scanning probe microscopy and two steps of wet chemical etching. The experimental transfer characteristics are obtained and compared with the numerical characteristics of the device. The simulation results are used to investigate the pinch-off mechanism, from the flat band to the off state. The study is based on the variation of the carrier density and the electric-field components. The device is a pinch-off transistor, which is normally in the on state and is driven into the off state by the application of a positive gate voltage. We demonstrate that the depletion starts from the bottom corner of the channel facing the gates and expands toward the center and top of the channel. Redistribution of the carriers due to the electric field emanating from the gates creates an electric field perpendicular to the current, toward the bottom...
