National Cheng Kung University

About: National Cheng Kung University is a education organization based out in Tainan City, Taiwan. It is known for research contribution in the topics: Population & Thin film. The organization has 49723 authors who have published 69799 publications receiving 1437420 citations. The organization is also known as: NCKU.

Improved air stability of perovskite solar cells via solution-processed metal oxide transport layers

Abstract: Lead halide perovskite solar cells have recently attracted tremendous attention because of their excellent photovoltaic efficiencies. However, the poor stability of both the perovskite material and the charge transport layers has so far prevented the fabrication of devices that can withstand sustained operation under normal conditions. Here, we report a solution-processed lead halide perovskite solar cell that has p-type NiOx and n-type ZnO nanoparticles as hole and electron transport layers, respectively, and shows improved stability against water and oxygen degradation when compared with devices with organic charge transport layers. Our cells have a p–i–n structure (glass/indium tin oxide/NiOx/perovskite/ZnO/Al), in which the ZnO layer isolates the perovskite and Al layers, thus preventing degradation. After 60 days storage in air at room temperature, our all-metal-oxide devices retain about 90% of their original efficiency, unlike control devices made with organic transport layers, which undergo a complete degradation after just 5 days. The initial power conversion efficiency of our devices is 14.6 ± 1.5%, with an uncertified maximum value of 16.1%. Using metal oxides for both the hole- and electron-transport layers in perovskite solar cells significantly improves their stability compared with devices containing organic transport layers.

A comparison of entecavir and lamivudine for HBeAg-positive chronic hepatitis B

Abstract: Methods In this phase 3, double-blind trial, we randomly assigned 715 patients with hepatitis B e antigen (HBeAg)–positive chronic hepatitis B who had not previously received a nucleoside analogue to receive either 05 mg of entecavir or 100 mg of lamivudine once daily for a minimum of 52 weeks The primary efficacy end point was histologic improvement (a decrease by at least two points in the Knodell necroinflammatory score, without worsening of fibrosis) at week 48 Secondary end points included a reduction in the serum HBV DNA level, HBeAg loss and seroconversion, and normalization of the alanine aminotransferase level Results Histologic improvement after 48 weeks occurred in 226 of 314 patients in the entecavir group (72 percent) and 195 of 314 patients in the lamivudine group (62 percent, P = 0009) More patients in the entecavir group than in the lamivudine group had undetectable serum HBV DNA levels according to a polymerase-chain-reaction assay (67 percent vs 36 percent, P<0001) and normalization of alanine aminotransferase levels (68 percent vs 60 percent, P = 002) The mean reduction in serum HBV DNA from baseline to week 48 was greater with entecavir than with lamivudine (69 vs 54 log [on a base-10 scale] copies per milliliter, P<0001) HBeAg seroconversion occurred in 21 percent of entecavir-treated patients and 18 percent of those treated with lamivudine (P = 033) No viral resistance to entecavir was detected Safety was similar in the two groups Conclusions Among patients with HBeAg-positive chronic hepatitis B, the rates of histologic, virologic, and biochemical improvement are significantly higher with entecavir than with lami vudine The safety profile of the two agents is similar, and there is no evidence of viral resistance to entecavir (ClinicalTrialsgov number, NCT00035633)

CH3NH3PbI3 Perovskite/Fullerene Planar‐Heterojunction Hybrid Solar Cells

Abstract: All-solid-state donor/acceptor planar-heterojunction (PHJ) hybrid solar cells are constructed and their excellent performance measured. The deposition of a thin C60 fullerene or fullerene-derivative (acceptor) layer in vacuum on a CH3 NH3 PbI3 perovskite (donor) layer creates a hybrid PHJ that displays the photovoltaic effect. Such heterojunctions are shown to be suitable for the development of newly structured, hybrid, efficient solar cells.