The H-terminated diamond films, which exhibit high surface conductivity, have been used in high-frequency and high-power electronic devices. In this paper, the surface conductive channel on specimens from the same dia...The H-terminated diamond films, which exhibit high surface conductivity, have been used in high-frequency and high-power electronic devices. In this paper, the surface conductive channel on specimens from the same diamond film was obtained by hydrogen plasma treatment and by heating under a hydrogen atmosphere, respectively, and the surface carrier transport characteristics of both samples were compared and evaluated. The results show that the carrier mobility and carrier density of the sample treated by hydrogen plasma are 15 cm^2·V^（-1）·s^（-1） and greater than 5 × 1012 cm^（-2）, respectively, and that the carrier mobilities measured at five different areas are similar. Compared to the hydrogen-plasma-treated specimen, the thermally hydrogenated specimen exhibits a lower surface conductivity, a carrier density one order of magnitude lower, and a carrier mobility that varies from 2 to 33 cm^2·V^（-1）·s^（-1）. The activated hydrogen atoms restructure the diamond surface, remove the scratches, and passivate the surface states via the etching effect during the hydrogen plasma treatment process, which maintains a higher carrier density and a more stable carrier mobility.展开更多
AIM: To investigate the therapeutic effects of nanophthalocyanine photosensitizers on an experimental rat choroidal neovescularization (CNV) model, as well as to evaluate the cytotoxicity of which on human retinal pig...AIM: To investigate the therapeutic effects of nanophthalocyanine photosensitizers on an experimental rat choroidal neovescularization (CNV) model, as well as to evaluate the cytotoxicity of which on human retinal pigment epithelia (HRPE) and human retinal endothelial cells (HRECs). METHODS: Two types of photosensitizers, G(1)-ZnPc(COOH)(8) and G(1)-ZnPc (COOH)(8)/m respectively, were administrated for photodynamic therapy (PDT) after a successful establishment of CNV model on Brown-Norway (BN) rats via fundus photocoagulation. The therapeutic effects of the two drugs were assessed through optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and transmission electron microscopy (TEM). For cytotoxicity tests, cell counting kit-8 (CCK-8) assays and changes of mitochondrial transmembrane potential (Delta psi m) were conducted on HRPE and HRECs after initial uptake of the two drugs. RESULTS: Both photosensitizers demonstrated an improvement of vascular leakage and closure of CNV 1 week after PDT as confirmed by fundus image, OCT, FFA and TEM. Two weeks after PDT, G(1)-ZnPc (COOH)(8)/m showed a better CNV closure effect versus G(1)-ZnPc(COON)(8)(P<0.05). A significant difference (P<0.01) was found in uptake of the two drugs in HRPE and HRECs, with no difference between the drugs(P>0.05). Both photosensitizers showed cytotoxicity on HRPE, but G(1)-ZnPc(COOH)(8)/m induced a lower cell viability. CONCLUSION: G(1)-ZnPc (COOH)(8)/m mediated PDT is better than G(1)-ZnPc (COOH)(8) in CNV closure and also have the advantage of fast metabolism leading to less side effect.展开更多
Effect of Ti(iso-C3H7O)4 treatment on the photoinduced charge carrier kinetics of nanocrystalline porous TiO2 films is studied by time-resolved microwave conductivity measurements. Analysis of the transient photocond...Effect of Ti(iso-C3H7O)4 treatment on the photoinduced charge carrier kinetics of nanocrystalline porous TiO2 films is studied by time-resolved microwave conductivity measurements. Analysis of the transient photoconductivity decays indicates that Ti(iso-C3H7O)4 treatment leads to an increased concentration of photogenerated charge carriers and a fast interfacial transfer rate of holes via the surface modification of the freshly growing TiO2 nanocrystallites.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51402013)the China Postdoctoral Science Foundation (No. 2015T80037)the Fundamental Research Funds for Central Universities (No. FRF-TP-15-052A2)
文摘The H-terminated diamond films, which exhibit high surface conductivity, have been used in high-frequency and high-power electronic devices. In this paper, the surface conductive channel on specimens from the same diamond film was obtained by hydrogen plasma treatment and by heating under a hydrogen atmosphere, respectively, and the surface carrier transport characteristics of both samples were compared and evaluated. The results show that the carrier mobility and carrier density of the sample treated by hydrogen plasma are 15 cm^2·V^（-1）·s^（-1） and greater than 5 × 1012 cm^（-2）, respectively, and that the carrier mobilities measured at five different areas are similar. Compared to the hydrogen-plasma-treated specimen, the thermally hydrogenated specimen exhibits a lower surface conductivity, a carrier density one order of magnitude lower, and a carrier mobility that varies from 2 to 33 cm^2·V^（-1）·s^（-1）. The activated hydrogen atoms restructure the diamond surface, remove the scratches, and passivate the surface states via the etching effect during the hydrogen plasma treatment process, which maintains a higher carrier density and a more stable carrier mobility.
基金National Natural Science Foundation of China(No.81070715)Innovative Platform Foundation of Fujian Province, China (No.2010Y2003)Key Research Projects Foundation of Fujian Province,China (No.2008Y0040)
文摘AIM: To investigate the therapeutic effects of nanophthalocyanine photosensitizers on an experimental rat choroidal neovescularization (CNV) model, as well as to evaluate the cytotoxicity of which on human retinal pigment epithelia (HRPE) and human retinal endothelial cells (HRECs). METHODS: Two types of photosensitizers, G(1)-ZnPc(COOH)(8) and G(1)-ZnPc (COOH)(8)/m respectively, were administrated for photodynamic therapy (PDT) after a successful establishment of CNV model on Brown-Norway (BN) rats via fundus photocoagulation. The therapeutic effects of the two drugs were assessed through optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and transmission electron microscopy (TEM). For cytotoxicity tests, cell counting kit-8 (CCK-8) assays and changes of mitochondrial transmembrane potential (Delta psi m) were conducted on HRPE and HRECs after initial uptake of the two drugs. RESULTS: Both photosensitizers demonstrated an improvement of vascular leakage and closure of CNV 1 week after PDT as confirmed by fundus image, OCT, FFA and TEM. Two weeks after PDT, G(1)-ZnPc (COOH)(8)/m showed a better CNV closure effect versus G(1)-ZnPc(COON)(8)(P<0.05). A significant difference (P<0.01) was found in uptake of the two drugs in HRPE and HRECs, with no difference between the drugs(P>0.05). Both photosensitizers showed cytotoxicity on HRPE, but G(1)-ZnPc(COOH)(8)/m induced a lower cell viability. CONCLUSION: G(1)-ZnPc (COOH)(8)/m mediated PDT is better than G(1)-ZnPc (COOH)(8) in CNV closure and also have the advantage of fast metabolism leading to less side effect.
基金This work was supported by National Research Fund for Fundamental Key Project(G2000028205)Innovative Foundation of Chinese Academy of Sciences(KGCX2-303-02)the Project of the National Natural Science Foundation of China(29873057).
文摘Effect of Ti(iso-C3H7O)4 treatment on the photoinduced charge carrier kinetics of nanocrystalline porous TiO2 films is studied by time-resolved microwave conductivity measurements. Analysis of the transient photoconductivity decays indicates that Ti(iso-C3H7O)4 treatment leads to an increased concentration of photogenerated charge carriers and a fast interfacial transfer rate of holes via the surface modification of the freshly growing TiO2 nanocrystallites.
