The Surfuce Adsorption Of Two-dimensional Graphene-like Materials

Since 2004,graphene has attracted a lot of scientists' attention due to its many excellent properties,but its zero band gap restricts the application in Optoelectronic devices.Although many researches have been used to open the band gap of graphene,these are difficult in practical operation.Therefore,searching for new two-dimensional(2D)graphene-like materials has become a hot issue.From long-term research results,we have found that tuning the electronic structure of 2D materials can broaden their potential applications.Based on this,the current paper introduced the theoretical research of changing the electronic structure of arsenene and tin sulfide(SnS)monolayers through surface adsorption.The main work and research results are shown as follows:1.Gray arsenic monolayer named as arsenene is a new kind of 2D semiconductor material.Herein,we focus on the electronic structures of the light atoms(such as B,C,N,O,F)adsorbed arsenene nanosheets by using first-principles calculations.The results show that most adatoms prefer to occupy the bridge site on the arsenene nanosheets except for the C adatom which prefer to valley site.The defect states can be found in the middle gap of the F adsorbed arsenene nanosheets,and the system is induced the n-type doping after N adatom adsorption.Moreover,O adatom has negligible effects on its electronic structures.In addition,B,C,N and F adatoms can induce the magnetism in the arsenene nanosheets.These studies will help to broaden the market for the design of sensors,detectors,and electronic devices.2.Based on first-principles calculations,we investigated the adsorption energy,structural parameters,and electronic and magnetic properties for the adsorption of different atoms,including light metals,hydrogen,oxygen,and 3d transition metals(TM)adatoms,on SnS monolayer.The results showed that Liand Al-atom adsorption can effectively induce n-type carriers,whereas O atom adsorption can produce p-type doping in the SnS monolayer.In addition,except for Ni atoms,the other 3d TM adatoms can induce magnetism in the SnS monolayer.Moreover,for Fe-and Co-atom adsorption,the occupied and unoccupied states belong to the same spin-channel.These results indicate that surface adsorption is an effective method to tune the electronic structures of the SnS monolayer.3.In our study,we systematically investigate the structural stability,electronic characteristics,average open circuit voltage,the lithium ion diffusion and strain on the system using density functional theory calculations.The results show that the most stable site is V site and the system can turn to be metal by embed li atom on arsenene monolayer.More importantly,by explicitly calculating the surface-to-surface ion diffusion,lower barriers of 150 meV is found and lower voltage of 0.65 V is found.Moreover,we also found that stretch strain could keep charged unchanged and strengthen the adsorption between Li atom and arsenic atom.This is likely the reason for the improved electrochemical properties found in nano-dimensional arsenene compared to their bulk counterparts.The results presented here provide valuable insights into the exploration of arsenene for potential applications.