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All-optical THz wave switching based on CH 3 NH 3 PbI 3 perovskites

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ABSTRACT

Hybrid structures of silicon with organic–inorganic perovskites are proposed for optically controllable switching of terahertz (THz) waves over a broad spectral range from 0.2 to 2THz. A 532-nm external laser was utilized to generate photoexcited free carriers at the devices and consequentially to control the terahertz amplitude modulation, obtaining a depth of up to 68% at a laser irradiance of 1.5 W/cm2. In addition, we compared the performances from three types of perovskite devices fabricated via different solution processing methods and suggested a stable and highly efficient THz switch based on a one-step processing. By this we demonstrated the possibility of perovskites as THz wave switching devices in addition to photovoltaics.

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Schematic diagram of optically controllable THz modulation of perovskite/Si.The THz pulse was generated using a 1-mm-thick ZnTe crystal and was guided through two off-axis parabolic mirrors (each with a focal length of 100 mm) and two polymethylpentene (TPX) lenses (each with a focal length of 50 mm). The 532-nm cw laser illuminated the surface at an obilique angle of 45° with a spot size ~2 mm larger than a 1-mm THz spot.
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f1: Schematic diagram of optically controllable THz modulation of perovskite/Si.The THz pulse was generated using a 1-mm-thick ZnTe crystal and was guided through two off-axis parabolic mirrors (each with a focal length of 100 mm) and two polymethylpentene (TPX) lenses (each with a focal length of 50 mm). The 532-nm cw laser illuminated the surface at an obilique angle of 45° with a spot size ~2 mm larger than a 1-mm THz spot.

Mentions: In the present experiment, we utilized a typical THz time-domain spectroscopy (THz-TDS) system with a spectral range from 0.2 to 2 THz based on a regenerative amplified femtosecond pulse laser system (Hurricane, Spectra-Physics). To modulate the THz wave transmission, an external continuous wave (cw) laser with a wavelength of 532 nm was used to illuminate a THz switching device at an oblique angle of 45° with a larger beam size than a THz spot, as shown in Fig. 1. We took note that the measurement of the THz modulation with hybrid perovskite/Si devices at the wavelength of 532 nm has never been reported even with the fact that green light is the most abundant spectral component in sunlight. So, in contrast to previous research on perovskite-based modulators with weak THz pulse and 400-nm optical pump22, we chose 532 nm of wavelength as optical pump and modulated intense THz pulse, which will be the realistic tool to characterize perovskite materials as solar devices.


All-optical THz wave switching based on CH 3 NH 3 PbI 3 perovskites
Schematic diagram of optically controllable THz modulation of perovskite/Si.The THz pulse was generated using a 1-mm-thick ZnTe crystal and was guided through two off-axis parabolic mirrors (each with a focal length of 100 mm) and two polymethylpentene (TPX) lenses (each with a focal length of 50 mm). The 532-nm cw laser illuminated the surface at an obilique angle of 45° with a spot size ~2 mm larger than a 1-mm THz spot.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5121641&req=5

f1: Schematic diagram of optically controllable THz modulation of perovskite/Si.The THz pulse was generated using a 1-mm-thick ZnTe crystal and was guided through two off-axis parabolic mirrors (each with a focal length of 100 mm) and two polymethylpentene (TPX) lenses (each with a focal length of 50 mm). The 532-nm cw laser illuminated the surface at an obilique angle of 45° with a spot size ~2 mm larger than a 1-mm THz spot.
Mentions: In the present experiment, we utilized a typical THz time-domain spectroscopy (THz-TDS) system with a spectral range from 0.2 to 2 THz based on a regenerative amplified femtosecond pulse laser system (Hurricane, Spectra-Physics). To modulate the THz wave transmission, an external continuous wave (cw) laser with a wavelength of 532 nm was used to illuminate a THz switching device at an oblique angle of 45° with a larger beam size than a THz spot, as shown in Fig. 1. We took note that the measurement of the THz modulation with hybrid perovskite/Si devices at the wavelength of 532 nm has never been reported even with the fact that green light is the most abundant spectral component in sunlight. So, in contrast to previous research on perovskite-based modulators with weak THz pulse and 400-nm optical pump22, we chose 532 nm of wavelength as optical pump and modulated intense THz pulse, which will be the realistic tool to characterize perovskite materials as solar devices.

View Article: PubMed Central - PubMed

ABSTRACT

Hybrid structures of silicon with organic–inorganic perovskites are proposed for optically controllable switching of terahertz (THz) waves over a broad spectral range from 0.2 to 2THz. A 532-nm external laser was utilized to generate photoexcited free carriers at the devices and consequentially to control the terahertz amplitude modulation, obtaining a depth of up to 68% at a laser irradiance of 1.5 W/cm2. In addition, we compared the performances from three types of perovskite devices fabricated via different solution processing methods and suggested a stable and highly efficient THz switch based on a one-step processing. By this we demonstrated the possibility of perovskites as THz wave switching devices in addition to photovoltaics.

No MeSH data available.


Related in: MedlinePlus