Semiconductor nanocrystals, or quantum dots (QDs), have garnered enormous attentions in large panel displays (e.g. Samsung QLED TVs). In this application, a sharp emission spectrum is critical because it reflects monochromaticity. However, the experimental study of single-dot emission spectrum is challenging because of the small size of QD. In this work, we develop theoretical framework to calculate the emission spectra of QDs. The role of shape, size and surface defects are studied within this framework.
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.