[paper] Graphene/4H-SiC/Graphene MSM UV-photodetector

An optimized Graphene/4H-SiC/Graphene MSM UV-photodetector operating
in a wide range of temperature 

H. Bencherif ¹, L. Dehimi1 ², G. Messina ³, P. Vincent ⁴, F. Pezzimenti ³, F. G. Della Corte ^{3 1}Laboratory of Metallic and Semiconductor Materials, University of Biskra, Biskra, DZ

²Faculty of Science, University of Batna 1, DZ

³DIIES, Mediterranea University of Reggio Calabria, Reggio Calabria, IT

⁴School of Electronics Engineering, KNU, 80 Daehakro, Buk-gu, Daegu, 702-701, KP

Abstract: In this paper, .an accurate analytical model has been developed to optimize the performance of an Interdigitated Graphene Electrode/p-silicon carbide (IGE/p-4H-SiC) Metal semiconductor Metal (MSM) photodetector operating in a wide range of temperatures. The proposed model considers different carrier loss mechanisms and can reproduce the experimental results well. An overall assessment of the electrodes geometrical parameters’ influence on the device sensitivity and speed performances was executed. Our results confirm the excellent ability of the suggested Graphene electrode system to decrease the unwanted shadowing effect. A responsivity of 238 μA/W was obtained under 325-nm illumination compared to the 16.7 μA/W for the conventional Cr-Pd/p-SiC PD. A photocurrent to- dark-current ratio (PDCR) of 5.75 × 105 at 300K and 270 at 500K was distinguished. The response time was found to be around 14 μs at 300K and 54.5 μs at 500K. Furthermore, the developed model serves as a fitness function for the multi objective optimization (MOGA) approach. The optimized IGE/p-4H-SiC MSM-PD design not only exhibits higher performance in terms of PDCR (7.2×105), responsivity (430A/cm2) and detectivity (1.3×1014 Jones) but also balances the compromise between ultrasensitive and high-speed figures of merit with a response time of 4.7 μs. Therefore, the proposed methodology permits to realize ultra-sensitive, high-speed SiC optoelectronic devices for extremely high temperature applications. 

FIG: a) Energy band diagram of Graphene/p-SiC/Graphene structure, b) Cross-sectional view of the suggested IGE/4H-SiC MSM UV-PD with interdigitated electrodes

Acknowledgments: This work was supported by DGRSDT Of Ministry of Higher education of Algeria. The work was done in the unit of research of materials and renewable energies (URMER).