First-Principles Prediction of the Electronic Structure and Carrier Mobility in Hexagonal Boron Phosphide Sheet and Nanoribbons

Abstract

Using density functional theory coupled to the Boltzmann transport equation with relaxation time approximation, we study the electronic structure and carrier mobility of graphene-like hexagonal boron phosphide ( h -BP) monolayer and H-terminated armchair boron phosphide nanoribbons (ABPNRs). Our results show that the carrier mobility can reach over 10 4 cm 2 V –1 s –1 for electron and 5 × 10 3 cm 2 V –1 s –1 for hole in monolayer sheet. The carrier mobility in the ABPNRs is in the range of 10 3 to 10 4 cm 2 V –1 s –1, and we find that the width of nanoribbon plays an important role in tuning the polarity of the carrier transport, which exhibits a distinct 3 p ( p is a positive integer) alternating behavior. The staggering oscillating behavior of mobility should be attributed to different bond characteristics of the edge states in the ABPNRs. Moreover, the H-terminated zigzag boron phosphide nanoribbons (ZBPNRs) have the characteristics of p-type semiconductors in electrical conduction, and the carrier mobility is increased with the width of the nanoribbons and no alternating size-dependent carrier polarity is found. The high carrier mobility and adjustable polarity of transport suggest that h -BP is a promising candidate material for application in future nanoelectronic devices.