TY - JOUR
T1 - Exceptional optoelectronic properties of hydrogenated bilayer silicene
AU - Huang, Bing
AU - Deng, Hui Xiong
AU - Lee, Hoonkyung
AU - Yoon, Mina
AU - Sumpter, Bobby G.
AU - Liu, Feng
AU - Smith, Sean C.
AU - Wei, Su Huai
PY - 2014
Y1 - 2014
N2 - Silicon is arguably the best electronic material, but it is not a good optoelectronic material. By employing first-principles calculations and the cluster-expansion approach, we discover that hydrogenated bilayer silicene (BS) shows promising potential as a new kind of optoelectronic material. Most significantly, hydrogenation converts the intrinsic BS, a strongly indirect semiconductor, into a direct-gap semiconductor with a widely tunable band gap. At low hydrogen concentrations, four ground states of single- and doublesided hydrogenated BS are characterized by dipole-allowed direct (or quasidirect) band gaps in the desirable range from 1 to 1.5 eV, suitable for solar applications. At high hydrogen concentrations, three well-ordered double-sided hydrogenated BS structures exhibit direct (or quasidirect) band gaps in the color range of red, green, and blue, affording white light-emitting diodes. Our findings open opportunities to search for new silicon-based light-absorption and light-emitting materials for earth-abundant, highefficiency, optoelectronic applications.
AB - Silicon is arguably the best electronic material, but it is not a good optoelectronic material. By employing first-principles calculations and the cluster-expansion approach, we discover that hydrogenated bilayer silicene (BS) shows promising potential as a new kind of optoelectronic material. Most significantly, hydrogenation converts the intrinsic BS, a strongly indirect semiconductor, into a direct-gap semiconductor with a widely tunable band gap. At low hydrogen concentrations, four ground states of single- and doublesided hydrogenated BS are characterized by dipole-allowed direct (or quasidirect) band gaps in the desirable range from 1 to 1.5 eV, suitable for solar applications. At high hydrogen concentrations, three well-ordered double-sided hydrogenated BS structures exhibit direct (or quasidirect) band gaps in the color range of red, green, and blue, affording white light-emitting diodes. Our findings open opportunities to search for new silicon-based light-absorption and light-emitting materials for earth-abundant, highefficiency, optoelectronic applications.
KW - Computational physics
KW - Condensed matter physics
KW - Graphene
UR - http://www.scopus.com/inward/record.url?scp=84904537023&partnerID=8YFLogxK
U2 - 10.1103/PhysRevX.4.021029
DO - 10.1103/PhysRevX.4.021029
M3 - Article
AN - SCOPUS:84904537023
SN - 2160-3308
VL - 4
JO - Physical Review X
JF - Physical Review X
IS - 2
M1 - 021029
ER -