光电流成像系统(Photon Current Imaging)
激光扫描分辨率< 0.02 um & 重复性< 0.1 μm
200µm x 200µm范围内高速成像 & 2D Mapping (x 40 objective)
拉曼光谱成像，PL，荧光光谱成像，光电流光谱成像，拉曼 mapping，PL mapping，photocurrent mapping，光电流mapping，荧光mapping
可任意设置激光扫描范围和扫描步进，激光扫描范围在40倍物镜下最大可达200µm x 200µm，激光扫描步进可低至0.1µm
图(d)二硫化钼的强度mapping成像，设置为激光扫描区域50um x50µm，激光扫描步进 0.3µm
图(e)二硫化钼的强度mapping成像，设置为激光扫描区域30um x30µm，激光扫描步进 0.1µm
图(f)二硫化钼的频率mapping成像，设置为激光扫描区域30um x30µm，激光扫描步进 0.1µm
（1） A Van Der Waals Homojunction: Ideal p–n Diode Behavior in MoSe2.pdf- Advanced Materials
摘要：We propose a semiconductorinsulatorsemiconductor (SIS) heterojunction diode consisting of monolayer (1-L) MoS2, hexagonal boron nitride (h-BN), and epitaxial p-GaN that can be applied to high-performance nanoscale optoelectronics. The layered materials of 1-L MoS2 and h-BN, grown by chemical vapor deposition, were vertically stacked by a wet-transfer method on a p-GaN layer. The final structure was verified by confocal photoluminescence and Raman spectroscopy. Currentvoltage (IV) measurements were conducted to compare the device performance with that of a more classical pn structure. In both structures (the pn and SIS heterojunction diode), clear current-rectifying characteristics were observed. In particular, a current and threshold voltage were obtained for the SIS structure that was higher compared to that of the pn structure. This indicated that tunneling is the predominant carrier transport mechanism. In addition, the photoresponse of the SIS structure induced by the illumination of visible light was observed by photocurrent measurements.
关键词：monolayer MoS2 . h-BN . GaN . semiconductorinsulatorsemiconductor diode . carrier tunneling
摘要：Micro-Raman spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy (TEM), oxygen vacancies, synchrotron X-ray absorption spectroscopy, magnetizations, optical band gaps, and photovoltaic (PV) effects have been studied in (Bi1 – xLax)FeO3 (BFO100xL) ceramics for x = 0.0,0.05, 0.10, and 0.15. XRD, Raman spectra, and TEM confirm a rhombohedral R3c symmetry with the tilted FeO6 oxygen octahedra in all compounds. The low-frequency Raman vibrations become broader and shift toward higher frequency as La3+ increases. Fe K-edge synchrotron X-ray absorptions reveal that Fe3+ valence and Fe–O–Fe bond angle are not modified by the La3+ substitution. All compounds exhibit a linear antiferromagnetic feature. Optical transmission reveals band gaps in the range of 2.22–2.24 eV. The heterostructures of indium tin oxide (ITO) film/(Bi1 – xLax)FeO3 ceramics/Au film show a p–n junction-like I–V characteristic behavior. The maximal PV power conversion efficiency can reach 0.19% in ITO/BFO15L/Au under illumination of k = 405 nm. A junction-like theoretical model can reasonably describe open-circuit voltage and short-circuit current as a function of illumination Intensity
摘要：This work reports enhanced photovoltaic (PV) responses of (Bi1 − xSmx)FeO3 (x = 0.0, 0.05, 0.10) ceramics (BFO100xSm) with ITO film under near-ultraviolet irradiation ( = 405 nm). The ceramics were characterized by micro-Raman scattering, high-resolution transmission electron microscopy, and synchrotron X-ray absorption spectroscopy (XAS). A rhombohedral R3c symmetry with tilted FeO6 octahedra has been
confirmed. The Fe K-edge absorption spectra reveal a slight shift toward higher energy as A-site Sm3+ substitution increases. The oxygen K-edge XAS reveals an enhancement of hybridization between the O 2p and unoccupied Fe 3d states due to Sm doping. The optical band gaps are in the range of 2.15–2.24 eV. The maximal PV power-conversion and external quantum efficiencies respectively reach 0.37% and 4.1% in the ITO/BFO5Sm/Au heterostructure. The PV responses can be described quantitatively by a p-n-junctionlike model. The domain structures and hybridization between the O 2p and Fe 3d states play important roles for the PV responses.
摘要：Soft X-ray absorption (XAS), transmission electron spectroscopy (TEM), Raman spectroscopy, and synchrotron XRD have been studied in B-site 0–2 mol% manganese (Mn) doped (Bi0.5Na0.5)0.925Ba0.075TiO3 (BN7.5BT) relaxor ferroelectric ceramics. High-resolution synchrotron XRD and TEM reveal two phase coexistence of rhombohedral R3c and tetragonal P4bm structures in 0 and 0.2%, and an orthorhombic structure in 1 and 2% Mn-doped BN7.5BT at room temperature. Raman spectra of 0% Mn reveal structural transition from two phase coexistence to tetragonal phase near 190 ◦C with a softening anomaly, while 0.2–2% Mn-doped BN7.5BT show softening behavior near 290 ◦C upon heating. Raman spectra and synchrotron XRD indicate that Mn doping can enhance structural thermal stability in BN7.5BT ceramics.© 2015 Elsevier Ltd. All rights reserved.
关键词：Relaxor ferroelectric ceramics; Raman spectroscopy; Synchrotron XRD; Phase transition
摘要：High-resolution Raman spectra, X-ray diffraction, oxygen vacancies, synchrotron X-ray absorption spectroscopy, magnetization, optical bandgap, and photovoltaic (PV) conversion have been studied in BiFeO3 (BFO) and (Bi0.93RE0.07)FeO3 (RE¼Dy, Gd, Eu and Sm) multiferroicceramics (7%Dy–BFO, 7%Gd–BFO, 7%Eu–BFO, and 7%Sm–BFO). 7%Dy–BFO exhibits a weak ferromagnetic behavior instead of the linearantiferromagnetic responses found in the other compounds. Optical transmissions reveal band gaps of 2.20–2.21 eV, which are slightly smallerthan 2.24 eV in pure BFO. The current vs. voltage (I–V) characteristic curves of indium tin oxide (ITO)/(Bi0.93RE0.07)FeO3 ceramics/Auheterostructures suggest a p–n-junction-like behavior. The maximal PV power-conversion efficiencies under illumination of λ¼405 nm in ITO/7%Dy–BFO/Au, ITO/7%Gd–BFO/Au, ITO/7%Eu–BFO/Au, and ITO/7%Sm–BFO/Au respectively reach 0.22%, 0.35%, 0.27%, and 0.24%,which are much larger than 0.017% in ITO/BFO/Au. The PV open-circuit voltage and short-circuit current can be reasonably described by ajunction model as a function of illumination intensity.
关键词：Rare-earth doped BiFeO3 ceramics; Raman vibration; Structure; Optical band gap; Photovoltaic conversion
产品标签：拉曼光谱成像,PL,荧光光谱成像,光电流光谱成像,拉曼 mapping,PL mapping,photocurrent mapping,光电流mapping,荧光mapping