番茄红素的生物活性及其应用

2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Design and fabrication of silicon nanowires towards efficient solar cells

The recent rise of semiconductor nanowires opens new opportunities for realizing high efficiency photovoltaic devices at low cost due to the unique one-dimensional structure with remarkable electrical and optical properties. Particularly, silicon nanowires (SiNWs), as one of the most earth-abundant materials, have been investigated worldwide to develop cost-effective solar cells. Great efforts have been devoted to fabricating ordered/disordered SiNWs using cost-effective approaches and achieving optimized structural parameters, such as array periodicity, nanowire morphology, length and diameter. Systematic theoretical investigations along with experimental studies on optical and electrical properties of SiNWs have been carried out. These efforts have led to obtaining remarkable improvement of the power conversion efficiency of SiNW solar cells from 10% in the last few years. However, till now, the power conversion efficiency of these SiNW solar cells is far from satisfactory for any commercial applications compared with the traditional bulk silicon solar cells. Further development of SiNW solar cells requires better understanding of the optical and electrical properties of the nanowire solar cells. Improvement in fabrication of high quality nanowires in a controlled fashion also plays a significant role in nanowire solar cell design and fabrication. To guide future development of SiNW solar cells, the recent work on SiNWs is reviewed. Following that, various techniques aiming to achieve high quality nanowires at low cost are introduced. Both bottom-up and top-down techniques are discussed. Then, electrical properties and various types of solar cells based on SiNWs are discussed. Finally challenges and prospects of SiNW solar cells are presented

铁调素(Hepcidin)在骨质矿化中的作用

2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

DMT1的结构及其基因表达调控

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

铁转运刺激因子研究进展

2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Cooperative Effects in the Photoluminescence of (In,Ga)As/GaAs Quantum Dot Chain Structures

Multilayer In0.4Ga0.6As/GaAs quantum dot (QD) chain samples are investigated by means of cw and time-resolved photoluminescence (PL) spectroscopy in order to study the peculiarities of interdot coupling in such nanostructures. The temperature dependence of the PL has revealed details of the confinement. Non-thermal carrier distribution through in-chain, interdot wave function coupling is found. The peculiar dependences of the PL decay time on the excitation and detection energies are ascribed to the electronic interdot coupling and the long-range coupling through the radiation field. It is shown that the dependence of the PL decay time on the excitation wavelength is a result of the superradiance effect

Quantum phase transition in a single-molecule quantum dot

Quantum criticality is the intriguing possibility offered by the laws of quantum mechanics when the wave function of a many-particle physical system is forced to evolve continuously between two distinct, competing ground states. This phenomenon, often related to a zero-temperature magnetic phase transition, can be observed in several strongly correlated materials such as heavy fermion compounds or possibly high-temperature superconductors, and is believed to govern many of their fascinating, yet still unexplained properties. In contrast to these bulk materials with very complex electronic structure, artificial nanoscale devices could offer a new and simpler vista to the comprehension of quantum phase transitions. This long-sought possibility is demonstrated by our work in a fullerene molecular junction, where gate voltage induces a crossing of singlet and triplet spin states at zero magnetic field. Electronic tunneling from metallic contacts into the $\rm{C_{60}}$ quantum dot provides here the necessary many-body correlations to observe a true quantum critical behavior.Comment: 8 pages, 5 figure

Nanowire Quantum Dot Surface Engineering for High Temperature Single Photon Emission

Generating single photons at high temperature remains a major challenge, particularly for group III-As and III-P materials widely used in optical communication. Here, we report a high temperature single photon emitter based on a “surface-free” GaAs quantum dot (QD) in a GaAsP nanowire. By using self-catalyzed vapor–liquid–solid growth and simple surface engineering, we can significantly enhance the optical signal from the QDs with a highly polarized photoluminescence at 750 nm. The “surface-free” nanowire quantum dots show photon antibunching up to 160 K and well resolved exciton lines as high as 220 K