Non-antireflective Scheme for Efficiency Enhancement of Cu(In,Ga)Se₂ Nanotip Array Solar Cells

We present systematic works in characterization of CIGS nanotip arrays (CIGS NTRs). CIGS NTRs are obtained by a one-step ion-milling process by a direct-sputtering process of CIGS thin films (CIGS TF) without a postselenization process. At the surface of CIGS NTRs, a region extending to 100 nm in depth with a lower copper concentration compared to that of CIGS TF has been discovered. After KCN washing, removal of secondary phases can be achieved and a layer with abundant copper vacancy (V_Cu) was left. Such compositional changes can be a benefit for a CIGS solar cell by promoting formation of Cd-occupied Cu sites (Cd_Cu) at the CdS/CIGS interface and creates a type-inversion layer to enhance interface passivation and carrier extraction. The raised V_Cu concentration and enhanced Cd diffusion in CIGS NTRs have been verified by energy dispersive spectrometry. Strengthened adhesion of Al:ZnO (AZO) thin film on CIGS NTRs capped with CdS has also been observed in SEM images and can explain the suppressed series resistance of the device with CIGS NTRs. Those improvements in electrical characteristics are the main factors for efficiency enhancement rather than antireflection

Chemical Inhibition of Human Thymidylate Kinase and Structural Insights into the Phosphate Binding Loop and Ligand-Induced Degradation

Targeting thymidylate kinase (TMPK) that catalyzes the phosphotransfer reaction for formation of dTDP from dTMP is a new strategy for anticancer treatment. This study is to understand the inhibitory mechanism of a previously identified human TMPK (hTMPK) inhibitor YMU1 (<b>1a</b>) by molecular docking, isothermal titration calorimetry, and photoaffinity labeling. The molecular dynamics simulation suggests that <b>1a</b> prefers binding at the catalytic site of hTMPK, whereas the hTMPK inhibitors that bear pyridino­[<i>d</i>]­isothiazolone or benzo­[<i>d</i>]­isothiazolone core structure in lieu of the dimethylpyridine-fused isothiazolone moiety in <b>1a</b> can have access to both the ATP-binding and catalytic sites. The binding sites of hTMPK inhibitors were validated by photoaffinity labeling and mass spectrometric studies. Taking together, <b>1a</b> and its analogues stabilize the conformation of ligand-induced degradation (LID) region of hTMPK and block the catalytic site or ATP-binding site, thus attenuating the ATP binding-induced closed conformation that is required for phosphorylation of dTMP