Ala Trabelsi - Academia.edu (original) (raw)
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Papers by Ala Trabelsi
Журнал технической физики, 2019
The effect of thermal annealing on the photovoltaic properties of a GaP/Si heterostructures obtai... more The effect of thermal annealing on the photovoltaic properties of a GaP/Si heterostructures obtained by plasma-enhanced atomic layer deposition under different conditions is examined. It is shown that in the structures containing amorphous GaP, annealing at 550°C leads to a sharp decrease in the quantum efficiency and open-circuit voltage, while in the structures with microcrystalline GaP on an epitaxial sublayer, the photovoltaic characteristics are improved. Annealing at a temperature of 750°C improves the photovoltaic characteristics in all the structures due to the diffusion of phosphorus atoms from GaP to Si and leads to the formation of a layer with n -type conductivity in the substrate. As the annealing temperature is increased to 900°C, the carrier lifetime in the silicon substrate decreases. It is shown that the atomic-layer-deposition technique is promising for the formation of a GaP nucleation layer on the surface of silicon before subsequent epitaxial growth.
Advances in Science, Technology and Engineering Systems Journal, 2020
The fifth-generation (5G) wireless system was implemented due to the massive connectivity, especi... more The fifth-generation (5G) wireless system was implemented due to the massive connectivity, especially Internet of Things (IoT) including industrial automation, Vehicle to Everything (V2X) communications, which is shelter an extensive range of applications services and use cases and Intelligent Transportation Systems (ITS). A cellular Non-Orthogonal Multiple Access (NOMA) based on radio resource allocation schemes need to be carefully designed to serve and support the diversity of applications and services, through increased safety and traffic efficiency usage of connected vehicle and ranging from infotainment services. In this paper, we develop a novel scheduling and resource allocation algorithm for vehicular communications named Priority-based Scheduling Algorithm for NOMA integrated V2X (PSA). The novel scheme could make the limited radio Resource Blocks (RB) to be assigned in a more efficiently manner to the different traffic classes (safety and non-safety traffic) imposed by V2X exigency, in order to improve the performances of the system in terms of average throughput, Quality of Service (QoS), Average Blocking Rate (ABR) and to ensure fairness criteria between Vehicular User Equipments (VUEs). The performance of PSA is shown for urban macro-cell and rural macro-cell scenarios and we compared it with the conventional OMA and some recent works for NOMA based allocation.
Журнал технической физики, 2019
The effect of thermal annealing on the photovoltaic properties of a GaP/Si heterostructures obtai... more The effect of thermal annealing on the photovoltaic properties of a GaP/Si heterostructures obtained by plasma-enhanced atomic layer deposition under different conditions is examined. It is shown that in the structures containing amorphous GaP, annealing at 550°C leads to a sharp decrease in the quantum efficiency and open-circuit voltage, while in the structures with microcrystalline GaP on an epitaxial sublayer, the photovoltaic characteristics are improved. Annealing at a temperature of 750°C improves the photovoltaic characteristics in all the structures due to the diffusion of phosphorus atoms from GaP to Si and leads to the formation of a layer with n -type conductivity in the substrate. As the annealing temperature is increased to 900°C, the carrier lifetime in the silicon substrate decreases. It is shown that the atomic-layer-deposition technique is promising for the formation of a GaP nucleation layer on the surface of silicon before subsequent epitaxial growth.
Advances in Science, Technology and Engineering Systems Journal, 2020
The fifth-generation (5G) wireless system was implemented due to the massive connectivity, especi... more The fifth-generation (5G) wireless system was implemented due to the massive connectivity, especially Internet of Things (IoT) including industrial automation, Vehicle to Everything (V2X) communications, which is shelter an extensive range of applications services and use cases and Intelligent Transportation Systems (ITS). A cellular Non-Orthogonal Multiple Access (NOMA) based on radio resource allocation schemes need to be carefully designed to serve and support the diversity of applications and services, through increased safety and traffic efficiency usage of connected vehicle and ranging from infotainment services. In this paper, we develop a novel scheduling and resource allocation algorithm for vehicular communications named Priority-based Scheduling Algorithm for NOMA integrated V2X (PSA). The novel scheme could make the limited radio Resource Blocks (RB) to be assigned in a more efficiently manner to the different traffic classes (safety and non-safety traffic) imposed by V2X exigency, in order to improve the performances of the system in terms of average throughput, Quality of Service (QoS), Average Blocking Rate (ABR) and to ensure fairness criteria between Vehicular User Equipments (VUEs). The performance of PSA is shown for urban macro-cell and rural macro-cell scenarios and we compared it with the conventional OMA and some recent works for NOMA based allocation.