Analyses of Responsivity and Quantum Efficiency of p-Si/i-β-FeSi2/n-Si Photodiodes

Abstract

Keywords: p-Si/i-β-FeSi 2 /n-Si photodiode, responsivity, quantum efficiencyIn this study the responsivity and quantum efficiency of p-Si/i-β-FeSi 2 /n-Si doubleheterostructure photodiodes and p-Si/i-Si/n-Si photodiodes are investigated by self-developed analytical methods. The dark current densities of both β-FeSi 2 and Si p-i-n photodiodes under the reverse bias condition are calculated by solving the diffusion current densities of minority carriers. The photocurrent densities of both p-i-n photodiodes under illumination with reverse bias are mainly calculated by solving the drift current densities in the depletion regions. When the β-FeSi 2 p-i-n photodiode incident wavelength, λ, is less than 0.6 µm, the magnitudes of responsivity and quantum efficiency are almost zero for different intrinsic thicknesses. The maximum responsivity, R = 0.65 A/W, and quantum efficiency, η = 65%, are both at λ = 1.2 µm and the intrinsic β-FeSi 2 layer thickness is 100 µm. The calculated responsivity of the Si p-i-n photodiode is consistent with the reported studies. Therefore, the analysis methods and results are valid in this work. These results indicate the high applicability of β-FeSi 2 to near-infrared photodiodes integrated with Si. Therefore, the p-Si/i-β-FeSi 2 /n-Si photodiode is a new highefficiency light sensor device applicable to optical fiber communications.

Smooth Surface with U-grooved Structures for Light-detecting Area of Photodetectors Using Dual-doped Tetramethyl Ammonium Hydroxide

“…The U-grooved structure photodetector exhibits a much higher performance because the large light-detecting surface area increases the number of photogenerated carriers at the surface of the U-grooved structure, preventing charge-carrier recombination. (30,35,36) Table 2 shows a comparison of the important parameters of the MSM and UMSM photodetectors. It was found that the electrical and optical properties of the UMSM photodetector were superior to those of the MSM photodetector of the same size: at an incident optical power of 6 mW, the UMSM photodetector had a photocurrent of 71.05 µA, approximately 2.5 times more than that of the MSM photodetector (28.92 µA).…”