N- and p-type doping of antimonene

Antimonene, monolayer antimony, was recently predicted to be a two-dimensional (2D) semiconductor with a blue photoresponse. N- and p-type doping of this material is essential for its future application in optoelectronic devices, but has not yet been carried out. Here, we introduce tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) as electron and hole dopants to attain n- and p-type antimonene semiconductors. Then, the electronic properties of the chemically doped antimonene are investigated based on comprehensive first-principles calculations. Through TTF modified antimonene, we acquire an n-type semiconductor with a deep donor state of 0.73 eV. Importantly, through TCNQ functionalized antimonene, a p-type semiconductor is achieved with a shallow acceptor state of 0.27 eV. Moreover, the co-adsorption of TTF and TCNQ on antimonene can significantly decrease the band-gaps to 0.15 and 0.12 eV in the one- and two-side configurations, respectively, exhibiting n-type semiconductance with shallow donor states. Such n- and p-type antimonene semiconductors may widen the application of two-dimensional semiconductors in electronics and optoelectronics.