The goal of this work was aimed to improve the power conversion efficiency of single crystalline silicon-based photovoltaic cells by using the solar spectral conversion principle, which employs an up-conversion phosph...The goal of this work was aimed to improve the power conversion efficiency of single crystalline silicon-based photovoltaic cells by using the solar spectral conversion principle, which employs an up-conversion phosphor to convert a low energy infrared photon to the more energetic visible photons to improve the spectral response. In this study, the surface of multicrystalline silicon solar cells was coated with an up-conversion molybdate phosphor to improve the spectral response of the solar cell in the near-infrared spectral range. The short circuit current （Isc）, open circuit voltage （Voc）, and conversion efficiency （η） of spectral conversion cells were measured. Preliminary experimental results revealed that the light conversion efficiency of a 1.5%–2.7% increase in Si-based cell was achieved.展开更多
We have prepared the graphene∕MoS2 heterostructure by a hydrothermal method, and presented its nonlinear absorption parameters and application as a nonlinear optical modulator in the mid-infrared region.Using the non...We have prepared the graphene∕MoS2 heterostructure by a hydrothermal method, and presented its nonlinear absorption parameters and application as a nonlinear optical modulator in the mid-infrared region.Using the nonlinear optical modulator, stable passively Q-switched operation of an Er^（3＋）-doped ZrF4-BaF2-LaF3-AlF3-NaF（ZBLAN） fiber laser at ~2.8 μm can be obtained. The Q-switched Er^（3＋）-doped ZBLAN fiber laser can yield per-pulse energy up to 2.2 μJ with the corresponding pulse width and pulse repetition rate of 1.9 μs and 45 kHz, respectively. Our results indicate that the graphene∕MoS2 heterostructure can be a robust optical modulator for pulsed lasers in the mid-infrared spectral range.展开更多
A simple and efficient approach was presented to enhance up-conversion emissions significantly for the Er:Al2O3 nanocrystals by Mo support (Er-Mo:Al2O3) with a 976 nm laser diode excitation. Mo support had evident eff...A simple and efficient approach was presented to enhance up-conversion emissions significantly for the Er:Al2O3 nanocrystals by Mo support (Er-Mo:Al2O3) with a 976 nm laser diode excitation. Mo support had evident effects on the phase structure and up-conversion emissions for the Er:Al2O3 nanocrystals, which promoted the -(Al,Er)2O3 transformed to -(Al,Er,Mo)2O3 phase. Compared with the Er:Al2O3, the maximal green and red up-conversion emissions intensities increased about 3×103 and 1.4×102 times for the Er-Mo:Al2O3 nanocrystals, respectively. It suggests that the enhancement of up-conversion emissions is caused by the high excited state energy transfer process from |4I15/2, 3T2> state of the Er3+-MoO42 dimer to the 4F7/2 level of Er3+.展开更多
基金Project supported by National Science Council of Taiwan (NSC98-2113-M-009-005-MY3)
文摘The goal of this work was aimed to improve the power conversion efficiency of single crystalline silicon-based photovoltaic cells by using the solar spectral conversion principle, which employs an up-conversion phosphor to convert a low energy infrared photon to the more energetic visible photons to improve the spectral response. In this study, the surface of multicrystalline silicon solar cells was coated with an up-conversion molybdate phosphor to improve the spectral response of the solar cell in the near-infrared spectral range. The short circuit current （Isc）, open circuit voltage （Voc）, and conversion efficiency （η） of spectral conversion cells were measured. Preliminary experimental results revealed that the light conversion efficiency of a 1.5%–2.7% increase in Si-based cell was achieved.
基金supported by the China Postdoctoral Science Foundation(No.2017M620349)the National Natural Science Foundation of China(Nos.61605166,11374251,and 61505124)+1 种基金the Research Foundation of Education Bureau of Hunan Province,China(No.17C1519)the Program for Changjiang Scholars and Innovative Research Team in University of China(No.IRT 17R91)
文摘We have prepared the graphene∕MoS2 heterostructure by a hydrothermal method, and presented its nonlinear absorption parameters and application as a nonlinear optical modulator in the mid-infrared region.Using the nonlinear optical modulator, stable passively Q-switched operation of an Er^（3＋）-doped ZrF4-BaF2-LaF3-AlF3-NaF（ZBLAN） fiber laser at ~2.8 μm can be obtained. The Q-switched Er^（3＋）-doped ZBLAN fiber laser can yield per-pulse energy up to 2.2 μJ with the corresponding pulse width and pulse repetition rate of 1.9 μs and 45 kHz, respectively. Our results indicate that the graphene∕MoS2 heterostructure can be a robust optical modulator for pulsed lasers in the mid-infrared spectral range.
基金supported by the National Natural Science Foundation of China (Grant No. 11004021)the Fundamental Research Funds for the Central Universities (Grant Nos. DC12010117 and DC120101174)
文摘A simple and efficient approach was presented to enhance up-conversion emissions significantly for the Er:Al2O3 nanocrystals by Mo support (Er-Mo:Al2O3) with a 976 nm laser diode excitation. Mo support had evident effects on the phase structure and up-conversion emissions for the Er:Al2O3 nanocrystals, which promoted the -(Al,Er)2O3 transformed to -(Al,Er,Mo)2O3 phase. Compared with the Er:Al2O3, the maximal green and red up-conversion emissions intensities increased about 3×103 and 1.4×102 times for the Er-Mo:Al2O3 nanocrystals, respectively. It suggests that the enhancement of up-conversion emissions is caused by the high excited state energy transfer process from |4I15/2, 3T2> state of the Er3+-MoO42 dimer to the 4F7/2 level of Er3+.
