http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Temperature-Dependent Photovoltaic Characterization of a CdTe/CdSe Nanocrystal’s Solar Cell
Huichao Zhang,Zhengyang Li,Jun Qian,Qiumei Guan,Xiaowei Du,Yiping Cui,Jiayu Zhang 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.2
An all-inorganic thin film solar cell was fabricated with colloidal CdTe and CdSe nanocrystals. Its temperaturedependent photovoltaic characterization was measured, and an open circuit voltage decay technique was used to determine the electron lifetime. The photovoltaic parameters, such as the exact carrier lifetime, were remarkably different between under low-temperature region and under temperature above 267 K. It is suggested that the temperature-dependent carrier conductivity results from a thermally-activated hopping process and this nanocrystals device is a kind of donor-acceptor solar cell.
Jiang, Bin,Zhang, Chunfeng,Wang, Xiaoyong,Park, Min Joo,Kwak, Joon Seop,Xu, Jian,Zhang, Huichao,Zhang, Jiayu,Xue, Fei,Xiao, Min WILEY‐VCH Verlag 2012 Advanced Functional Materials Vol.22 No.15
<P><B>Abstract</B></P><P>The energy transfer (ET) between InGaN/GaN multiple‐quantum‐well (MQW) nanorods (NRs) and semiconductor nanocrystals (NCs) for efficient color conversion is studied. An exceptional contribution of carrier transport confinement to the ET mechanisms is observed in the proximal side‐wall coupling system, which consists of InGaN/GaN NRs and CdSe NCs. Under relatively low or high excitation, the ET rate shows different carrier‐density dependence, resulting from different electron‐hole configurations, i.e., bound excitons and free carriers. In the localized exciton regime, the ET rate decreases when increasing temperature from 20 K to 200 K. However, in the free‐carrier regime, the ET rate varies insignificantly in the same temperature range. The temperature dependence in this NR‐NC coupling system is different from that in the previously studied planar MQW‐NC coupling system. It is suggested that the carrier transport confinement in NRs is a major factor for these divergences. The highly efficient ET with efficiency up to 80% shows a promising potential of using such NR‐NC coupled structures for ET‐pumped, NC‐based, light‐emitting devices.</P>
Simulation of Grid-Connected Solar Micro-inverter Based on Fuzzy PI Controller
Weiliang Liu,Changliang Liu,Huichao Zhang,Yongjun Lin,Liangyu Ma 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10
Grid-connected solar micro-inverter is a highly nonlinear and time-varying system, so it is difficult to achieve good control effect using traditional PI controller. In this paper, small signal analysis model of micro-inverter is established, grid-connected current control strategy composed of fuzzy PI controller and grid voltage feed-forward is put forward, and the initial parameters of PI controller is optimized using the genetic algorithm. Simulation results show that the control strategy has the virtues of good robustness, small dynamic deviation, and could reduce the harmonic content of grid-connected current.
Huichao He,Yunhuai Zhang,Peng Xiao,Yannan Yang,Qing Lou,Fei Yang 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.5
Ni nanoparticles-TiO2 nanotube arrays (Ni/TiO2NTs) composites were prepared by pulsed electrodeposition method and subsequently characterized by means of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The FESEM results showed that highly dispersed Ni nanoparticles were not only loaded on the top of the TiO2NTs but also within the tubular structure, and the particle size of Ni prepared at different current amplitude (100, 200 and 300 mA·cm−2) was in the range of 15 to 70 nm. The electrochemical studies indicated that Ni nanoparticles loaded on the highly ordered TiO2NTs are readily accessible for electrochemical reactions, which improve the efficiency of the Ni nanoparticles and TiO2NTs. A maximum specific capacitance (27.3 mF.cm−2) was obtained on the Ni/TiO2NTs composite electrode that prepared at a current of 200 mA.cm−2, and the electrode also exhibited excellent electrochemical stability.
He, Huichao,Zhang, Yunhuai,Xiao, Peng,Yang, Yannan,Lou, Qing,Yang, Fei Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.5
Ni nanoparticles-$TiO_2$ nanotube arrays (Ni/$TiO_2NTs$) composites were prepared by pulsed electrodeposition method and subsequently characterized by means of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The FESEM results showed that highly dispersed Ni nanoparticles were not only loaded on the top of the $TiO_2NTs$ but also within the tubular structure, and the particle size of Ni prepared at different current amplitude (100, 200 and 300 $mA{\cdot}cm^{-2}$) was in the range of 15 to 70 nm. The electrochemical studies indicated that Ni nanoparticles loaded on the highly ordered $TiO_2NTs$ are readily accessible for electrochemical reactions, which improve the efficiency of the Ni nanoparticles and $TiO_2NTs$. A maximum specific capacitance (27.3 $mF.cm^{-2}$) was obtained on the Ni/$TiO_2NTs$ composite electrode that prepared at a current of 200 $mA.cm^{-2}$, and the electrode also exhibited excellent electrochemical stability.
A SERIES OF MONODISPERSE SILVER NANOPARTICLES BY A ONE-POT SYNTHESIS
LUPING TANG,Huichao Zhang,Yiping Cui,Jiayu Zhang,YONGHONG YE,SHENFEI ZONG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.1
A series of monodisperse Ag nanoparticles (Ag NPs), whose size can be tuned between 2 nm and34 nm, have been successfully synthesized in one pot by controlling the growth time. The stan-dard deviation of the small-size Ag NPs is 12% while that of the large-size ones is 15%. During thesynthesis process, sodium borohydride and sodium dodecyl sulfate were used as reducing agentand surfactant, respectively, and the e®ect of the synthesis parameters on the size-tuning rangeand the size distribution of Ag NPs was studied to get the optimum growth condition. Moreover,surface enhanced Raman scattering (SERS) spectra were analyzed to explore the synthesismechanism of Ag NPs
Copper Acetate Etching of Colloidal CdSe Nanocrystals
Boping Yang,Huichao Zhang,Jiayu Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.2
Colloidal CdSe nanocrystals (NCs) were etched after Se/TBP and Zinc stearate/ODE were injected into the mixture of as-prepared CdSe NCs and Copper (II) acetate in ODE solvent. Spectroscopic and structural investigations demonstrate the etching process. Along with the etching time, both the absorption and photoluminescence (PL) spectra of etched NCs showed blue-shift while the transmission electron microscopy (TEM) images indicated that the size of the NCs became from 5.6 nm to 2.6 nm. X-ray diffraction (XRD) patterns suggested that no other clusters or core/shell NCs were formed in the etching process and inductively coupled plasma (ICP) data demonstrated that only selenium and cadmium comprised the etched NCs. Electronic paramagnetic resonance (EPR) spectra indicated the deoxidization of Cu2+ ions and suggested the etching mechanism through cation exchange process.
Effect of Oxygen Vacancies on Photocatalytic Efficiency of TiO2 Nanotubes Aggregation
Feila Liu,Lu Lu,Peng Xiao,Huichao He,Lei Qiao,Yunhuai Zhang 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.7
Aggregation of titania nanotubes (TNTs) fabricated by hydrothermal method were calcined in air and dry nitrogen; Changes in morphology and crystallinity of the nanotubes were studied by means of TEM, EDX, and XPS. EDX patterns and XPS spectra proved that there were a certain densities of oxygen vacancies in TNTs annealed in N2. The photocatalysis experiments revealed TNTs/N2 possesses significantly higher photocatalytic efficiency than TNTs annealed in dry air to degrade methylene blue. The correlation between oxygen vacancies and photocatalytic property may be attributed to: 1) oxygen vacancies might have affected results on water molecules adsorption and increase of the hydroxyl concentration; and 2) oxygen vacancies resulted in some changes in electronic structure of TNTs/N2 aggregation and Fermi level extends into the conducting band.
Effect of Oxygen Vacancies on Photocatalytic Efficiency of TiO<sub>2</sub> Nanotubes Aggregation
Liu, Feila,Lu, Lu,Xiao, Peng,He, Huichao,Qiao, Lei,Zhang, Yunhuai Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.7
Aggregation of titania nanotubes (TNTs) fabricated by hydrothermal method were calcined in air and dry nitrogen; Changes in morphology and crystallinity of the nanotubes were studied by means of TEM, EDX, and XPS. EDX patterns and XPS spectra proved that there were a certain densities of oxygen vacancies in TNTs annealed in $N_2$. The photocatalysis experiments revealed TNTs/$N_2$ possesses significantly higher photocatalytic efficiency than TNTs annealed in dry air to degrade methylene blue. The correlation between oxygen vacancies and photocatalytic property may be attributed to: 1) oxygen vacancies might have affected results on water molecules adsorption and increase of the hydroxyl concentration; and 2) oxygen vacancies resulted in some changes in electronic structure of TNTs/$N_2$ aggregation and Fermi level extends into the conducting band.