Helium incorporation induced direct-gap silicides  

作　　者：Shicong Ding Jingming Shi Jiahao Xie Wenwen Cui Pan Zhang Kang Yang Jian Hao Lijun Zhang Yinwei Li 

机构地区：[1]Laboratory of Quantum Functional Materials Design and Application,School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou,China [2]State Key Laboratory of Superhard Materials,Key Laboratory of Automobile Materials of MOE,and College of Materials Science and Engineering,Jilin University,Changchun,China [3]Shandong Key Laboratory of Optical Communication Science and Technology,School of Physical Science and Information Technology of Liaocheng University,Liaocheng,China

出　　处：《npj Computational Materials》2021年第1期809-816,共8页计算材料学（英文）

基　　金：The authors acknowledge funding from the NSFC under grants Nos.12074154,11804129,11722433,and 11804128;the funding from the Science and Technology Project of Xuzhou under grant No.KC19010;Y.L.acknowledges the funding from the Six Talent Peaks Project and 333 High-level Talents Project of Jiangsu Province;S.D.acknowledges the founding from Postgraduate Research and Practice Innovation Program of Jiangsu Province No.KYCX20_2223.

摘　　要：The search of direct-gap Si-based semiconductors is of great interest due to the potential application in many technologically relevant fields.This work examines the incorporation of He as a possible route to form a direct band gap in Si.Structure predictions and first-principles calculations show that He and Si,at high pressure,form four dynamically stable phases of Si_(2)He(oP36-Si_(2)He,tP9-Si_(2)He,mC18-Si_(2)He,and mC12-Si_(2)He).All phases adopt host–guest structures consisting of a channel-like Si host framework filled with He guest atoms.The Si frameworks in oP36-Si2He,tP9-Si2He,and mC12-Si_(2)He could be retained to ambient pressure after removal of He,forming three pure Si allotropes.Among them,oP36-Si_(2)He and mC12-Si_(2)He exhibit direct band gaps of 1.24 and 1.34 eV,respectively,close to the optimal value(~1.3 eV)for solar cell applications.Analysis shows that mC12-Si_(2)He with an electric dipole transition allowed band gap possesses higher absorption capacity than cubic diamond Si,which makes it to be a promising candidate material for thin-film solar cell.

关 键 词：allowed FILLED AMBIENT 

分 类 号：O47[理学—半导体物理]