Prof. Dr. Peter Hess is professor (emeritus) of Physical Chemistry at the University of Heidelberg since 1980. He was research fellow at the Department of Chemistry, University of California (Berkeley, USA) and was regularly visiting scientist at Almaden Research Laboratories, IBM, San Jose, California. He has been active in several research field, e.g., laser-based photoacoustics in gases, used in trace gas analysis. Moreover, he employed laser-based surface acoustic waves (SAWs), wedge waves (WWs), and solitary surface waves to study all-optical nondestructive evaluation (NDE), linear elastic properties, and fracture strength of solids.  As professor emeritus he became interested in bonding, structure, and mechanical behavior of 2D materials, which is his current research topic. He produced more than 300 publications in scientific journals and was editor or co-editor of 6 books. He has received the James Smith prize of the International Photoacoustic and Photothermal Association (IPPA) for the application of linear and nonlinear elastic waves in materials science and served as director of the Technology Transfer Center Heidelberg for laser processing.

• Introduction.- Elemental Group-IIA Monolayers.- Elemental Group-IIIA Monolayers.- Groups IIA‒IVA, IIIA‒IVA.- Elemental Group-IVA Monolayers.- Binary Heteroelemental Group IVA-IVA Monolayers.- Group IIIA-VA Monolayers.- Group-VA Monolayers.- Binary Group VA-VA Monolayers.- Group IVA-VA Monolayers.- Group VIA Monolayers.- Binary Group IIIA-VIA Monolayers.- Group IVA-VIA Monolayers.- Group IVB Transition-Metal Dichalcogenide Monolayers.- Group VB-VIA Monolayers.- Group VIB Transition-Metal Dioxide and Dichalcogenide Monolayers.- Group XB Transition-Metal Dioxide and XB Dichalcogenide Monolayers.- Summary and Outlook.

Prof. Dr. Peter Hess is professor (emeritus) of Physical Chemistry at the University of Heidelberg since 1980. He was research fellow at the Department of Chemistry, University of California (Berkeley, USA) and was regularly visiting scientist at Almaden Research Laboratories, IBM, San Jose, California. He has been active in several research field, e.g., laser-based photoacoustics in gases, used in trace gas analysis. Moreover, he employed laser-based surface acoustic waves (SAWs), wedge waves (WWs), and solitary surface waves to study all-optical nondestructive evaluation (NDE), linear elastic properties, and fracture strength of solids.  As professor emeritus he became interested in bonding, structure, and mechanical behavior of 2D materials, which is his current research topic. He produced more than 300 publications in scientific journals and was editor or co-editor of 6 books. He has received the James Smith prize of the International Photoacoustic and Photothermal Association (IPPA) for the application of linear and nonlinear elastic waves in materials science and served as director of the Technology Transfer Center Heidelberg for laser processing.

• Introduction.- Elemental Group-IIA Monolayers.- Elemental Group-IIIA Monolayers.- Groups IIA‒IVA, IIIA‒IVA.- Elemental Group-IVA Monolayers.- Binary Heteroelemental Group IVA-IVA Monolayers.- Group IIIA-VA Monolayers.- Group-VA Monolayers.- Binary Group VA-VA Monolayers.- Group IVA-VA Monolayers.- Group VIA Monolayers.- Binary Group IIIA-VIA Monolayers.- Group IVA-VIA Monolayers.- Group IVB Transition-Metal Dichalcogenide Monolayers.- Group VB-VIA Monolayers.- Group VIB Transition-Metal Dioxide and Dichalcogenide Monolayers.- Group XB Transition-Metal Dioxide and XB Dichalcogenide Monolayers.- Summary and Outlook.