We estimated the catalytic activity for the hydrogen evolution reaction (HER) at the anion vacancy of 40 two-dimensional transition metal dichalcogenides (TMDs) using hydrogen adsorption free energy as the activity descriptor. ZrSe2 and ZrTe2 are expected to be promising HER catalyst at low vacancy density and other several TMDs are suggested at high vacancy densities. In addition, we verified that the vacancy formation energy, HOMO and LUMO mainly contributes to the hydrogen adsorption energy.
Deficiency in p-type transparent semiconductors hinders the general application of the transparent semiconductor devices in spite of enormous efforts to discover them. We report a highly accurate and efficient descriptor for p-type dopability—the hydrogen impurity energy. Using the hydrogen descriptor, binary oxides and a selected pool of ternary compounds are screened. As a result of the screening, La2O2Te and CuLiO are proposed as promising p-type oxides.
We modelled process-dependent structures of vapor-deposited amorphous organic films using molecular dynamics simulation that mimics vapor-deposition process. The dependence of molecular orientation on various factors such as substrate temperature, molecular shape, and material composition was theoretically investigated. We suggested the formation mechanism of molecular orientation during the vapor-deposition process. We also found that the higher mobility of oriented films can be explained with site energy correlation.