Palladium(Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics.However,the synthesis of large-scale uniform Pd...Palladium(Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics.However,the synthesis of large-scale uniform PdS and PdS_(2)nanofilms(NFs)remains an enormous challenge.In this work,2-inch wafer-scale PdS and PdS_(2) NFs with excellent stability can be controllably prepared via chemical vapor deposition combined with electron beam evaporation technique.The thickness of the pre-deposited Pd film and the sulfurization temperature are critical for the precise synthesis of PdS and PdS_(2) NFs.A corresponding growth mechanism has been proposed based on our experimental results and Gibbs free energy calculations.The electrical transport properties of PdS and PdS_(2) NFs were explored by conductive atomic force microscopy.Our findings have achieved the controllable growth of PdS and PdS_(2) NFs,which may provide a pathway to facilitate PdS and PdS_(2) based applications for next-generation high performance optoelectronic devices.展开更多
Optical power splitters(OPSs) are essential components in the photonic integrated circuits. Considerable power splitting schemes have been reported on the silicon-on-insulator platform. However, the corresponding devi...Optical power splitters(OPSs) are essential components in the photonic integrated circuits. Considerable power splitting schemes have been reported on the silicon-on-insulator platform. However, the corresponding device lengths are enlarged, and polarization-sensitive operations are usually encountered when the splitting channels are increased from two to five. In this paper, a novel power splitting model is proposed to overcome these limitations.Here, fan-out bending subwavelength grating(FBSWG) metamaterials instead of classical straight SWGs are leveraged to expand the input TE/TM mode in an ultracompact region and further bend its wavefronts. By using N-angled tapers to match bending wavefronts, the light expanded by FBSWGs can be collected and evenly distributed into N output channels. Based on such a model, three OPSs are designed and experimentally demonstrated, which are the shortest polarization-independent 1 × 3, 1 × 4, and 1 × 5 OPSs reported until now to our knowledge. The characterizations show low insertion losses(<1.2 dB, <1.35 dB, and <1.65 dB) and uniformities(<0.9 dB, <1 d B, and <1 d B) over bandwidths of 54 nm, 49 nm, and 38 nm for the 1 × 3, 1 × 4, and 1 × 5OPSs, respectively. For the first time, an ultracompact device length of <4.3 μm and a polarization-independent operation can be maintained simultaneously as the output splitting channels are increased.展开更多
基金supported by National Natural Science Foundation of China (No.11974301)Key Research and Development Program of Hunan Province (No.2022GK2007)+2 种基金Key Project from Department Education of Hunan Province (No.22A0123)Scientific Research Fund of Hunan Provincial Education Department (No.21B0136)National college students innovation and entrepreneurship training program (No.S202310530016)。
文摘Palladium(Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics.However,the synthesis of large-scale uniform PdS and PdS_(2)nanofilms(NFs)remains an enormous challenge.In this work,2-inch wafer-scale PdS and PdS_(2) NFs with excellent stability can be controllably prepared via chemical vapor deposition combined with electron beam evaporation technique.The thickness of the pre-deposited Pd film and the sulfurization temperature are critical for the precise synthesis of PdS and PdS_(2) NFs.A corresponding growth mechanism has been proposed based on our experimental results and Gibbs free energy calculations.The electrical transport properties of PdS and PdS_(2) NFs were explored by conductive atomic force microscopy.Our findings have achieved the controllable growth of PdS and PdS_(2) NFs,which may provide a pathway to facilitate PdS and PdS_(2) based applications for next-generation high performance optoelectronic devices.
基金Scientific Research Foundation of the Graduate School of Southeast University(YBPY2135)Natural Science Foundation of Jiangsu Province(BK20211163)National Natural Science Foundation of China(11574046,12004092)。
文摘Optical power splitters(OPSs) are essential components in the photonic integrated circuits. Considerable power splitting schemes have been reported on the silicon-on-insulator platform. However, the corresponding device lengths are enlarged, and polarization-sensitive operations are usually encountered when the splitting channels are increased from two to five. In this paper, a novel power splitting model is proposed to overcome these limitations.Here, fan-out bending subwavelength grating(FBSWG) metamaterials instead of classical straight SWGs are leveraged to expand the input TE/TM mode in an ultracompact region and further bend its wavefronts. By using N-angled tapers to match bending wavefronts, the light expanded by FBSWGs can be collected and evenly distributed into N output channels. Based on such a model, three OPSs are designed and experimentally demonstrated, which are the shortest polarization-independent 1 × 3, 1 × 4, and 1 × 5 OPSs reported until now to our knowledge. The characterizations show low insertion losses(<1.2 dB, <1.35 dB, and <1.65 dB) and uniformities(<0.9 dB, <1 d B, and <1 d B) over bandwidths of 54 nm, 49 nm, and 38 nm for the 1 × 3, 1 × 4, and 1 × 5OPSs, respectively. For the first time, an ultracompact device length of <4.3 μm and a polarization-independent operation can be maintained simultaneously as the output splitting channels are increased.
