By observing two-photon response and anisotropy of the light-induced voltage in Al-Si Schottky barrier potential,it is certified from the experimental and theoretical analysis that the built-in electric field generate...By observing two-photon response and anisotropy of the light-induced voltage in Al-Si Schottky barrier potential,it is certified from the experimental and theoretical analysis that the built-in electric field generated by the Schottky barrier potential will induce the phenomena of optical rectification in Si photodiode.Thus,it is deduced that there must be double-frequency absorption caused by phase-mismatch in the mechanism of two-photon response of Si photodiode.If the intensity of the built-in electric field is strong enough,the double-frequency absorption will be the main factor of the two-photon response,which is different from the conventional opinion that the two-photon response is just the two-photon absorption.展开更多
Photodiode＇s reflectance plays an important role regarding the relation between responsivity and the incident flux. In this work we analyze how the spectral reflectance changes among photodiodes from the same manufac...Photodiode＇s reflectance plays an important role regarding the relation between responsivity and the incident flux. In this work we analyze how the spectral reflectance changes among photodiodes from the same manufacturer and batch and how the reflectance of three standard photodiodes has drifted during six years. The results show that the reflectance changes from diode to diode within the same batch and also show that the reflectance ofphotodiodes changes on time. This ageing is spectraUy dependent.展开更多
Two-dimensional(2D) ternary materials have sprung up in a broad variety of optoelectronic applications due to their robust degree of freedom to design the physical properties of the materials through adjusting the sto...Two-dimensional(2D) ternary materials have sprung up in a broad variety of optoelectronic applications due to their robust degree of freedom to design the physical properties of the materials through adjusting the stoichiometric ratio. However, the controlled growth of high-quality 2D ternary materials with good chemical stoichiometry remains challenging, which severely impedes their further development and future device applications. Herein, we synthesize ternary Bi_(2)Te_(2)Se(BTS) flakes with a thickness down to 4 nm and a lateral dimension about 60 μm by an atmospheric-pressure solid source thermal evaporation method on a mica substrate. The phonon vibration and electrical transportation of 2D BTS are respectively investigated by temperature-dependent Raman spectrum and conductivity measurements. Furthermore, the photodetector based on 2D BTS exhibits excellent performance with a high light on/off ratio of 1300(365 nm), a wide spectral response range from 365 to 980 nm, and an ultra-fast response speed up to 2 μs. In addition, its electrical and photoelectric properties can be modulated by the gate voltage, offering an improved infrared responsivity to 2.74 A W^(-1) and an on/off ratio of 2266 under 980 nm. This work introduces an effective approach to obtain 2D BTS flakes and demonstrates their excellent prospects in optoelectronics.展开更多
文摘By observing two-photon response and anisotropy of the light-induced voltage in Al-Si Schottky barrier potential,it is certified from the experimental and theoretical analysis that the built-in electric field generated by the Schottky barrier potential will induce the phenomena of optical rectification in Si photodiode.Thus,it is deduced that there must be double-frequency absorption caused by phase-mismatch in the mechanism of two-photon response of Si photodiode.If the intensity of the built-in electric field is strong enough,the double-frequency absorption will be the main factor of the two-photon response,which is different from the conventional opinion that the two-photon response is just the two-photon absorption.
文摘Photodiode＇s reflectance plays an important role regarding the relation between responsivity and the incident flux. In this work we analyze how the spectral reflectance changes among photodiodes from the same manufacturer and batch and how the reflectance of three standard photodiodes has drifted during six years. The results show that the reflectance changes from diode to diode within the same batch and also show that the reflectance ofphotodiodes changes on time. This ageing is spectraUy dependent.
基金supported by the National Natural Science Foundation of China (21825103)Hubei Provincial Natural Science Foundation of China (2019CFA002)the Fundamental Research Funds for the Central Universities (2019kfy XMBZ018)。
文摘Two-dimensional(2D) ternary materials have sprung up in a broad variety of optoelectronic applications due to their robust degree of freedom to design the physical properties of the materials through adjusting the stoichiometric ratio. However, the controlled growth of high-quality 2D ternary materials with good chemical stoichiometry remains challenging, which severely impedes their further development and future device applications. Herein, we synthesize ternary Bi_(2)Te_(2)Se(BTS) flakes with a thickness down to 4 nm and a lateral dimension about 60 μm by an atmospheric-pressure solid source thermal evaporation method on a mica substrate. The phonon vibration and electrical transportation of 2D BTS are respectively investigated by temperature-dependent Raman spectrum and conductivity measurements. Furthermore, the photodetector based on 2D BTS exhibits excellent performance with a high light on/off ratio of 1300(365 nm), a wide spectral response range from 365 to 980 nm, and an ultra-fast response speed up to 2 μs. In addition, its electrical and photoelectric properties can be modulated by the gate voltage, offering an improved infrared responsivity to 2.74 A W^(-1) and an on/off ratio of 2266 under 980 nm. This work introduces an effective approach to obtain 2D BTS flakes and demonstrates their excellent prospects in optoelectronics.
