Superior p‐Type Surface Doping of Cubic Boron Nitride via MoO₃ Adsorption

Abstract

Cubic boron nitride (c-BN) is a potential candidate material for electronic and optoelectronic devices under extreme conditions, while the difficulty in conventional doping severely hinders its applications. Herein, by first-principles calculation, an efficient p-type doping on the c-BN surface (areal hole density of 8.82 × 10 13 cm −2 and hole mobility of 826 cm 2 V −1 s −1 at room temperature) is realized by the surface charge transfer mechanism with the MoO 3 molecule having a high electron affinity as the dopant. The MoO 3 molecule draws electrons from the c-BN, making the hole accumulation on the c-BN surface. The areal hole density of c-BN enhances with the increase of MoO 3 molecule density and reaches the maximum (1.24 × 10 14 cm −2 ) with MoO 3 monolayer adsorption. The optical absorption coefficient significantly increases in the infrared and visible regions. The superior p-type doping for c-BN is also achieved by adsorbing transistor metal oxides with the high electron affinity values (such as ReO 3 , CrO 3 , WO 3 , and V 2 O 5 ). This study opens a novel avenue for promoting c-BN applied in optoelectronic devices.

Structural and electronic properties of pristine and hydrogen-terminated c-BN(100) surfaces

“…However, for H-terminated c-BN(100) surface, each surface N (B) atom is bonded with two B (N) atoms and one H atom. It is supposed that the surface atoms should be saturated by fictitious H with other charges, 35 which was proved in the GaAs quantum dot. 34 Thus, we used the virtual H atoms with 0.5, 0.75, 1.25, and 1.5 e valence electrons and conventional H atoms to terminate the surface atoms for each structure, and performed AIMD simulations to obtain the structural evolutions.…”

“…31,32 This approach is widely applied to build the structural models for polar semiconductors. 15,33–35 Based on the simple chemical consideration of a covalent bond, the fractional 0.75 (1.25) charged H atoms are generally used to terminate the N (B) dangling bonds on c-BN(111) surface. 33 Note that the surface N (B) atom on the c-BN(111) surface is connected with three B (N) atoms and one H atom.…”

Degenerate p-Type and n-Type Doping of Diamane by Molecular Adsorption

“…Spin splitting occurs for TCNQ/H-diamane, MoO 3 /H-diamane, CrO 3 /H-diamane, WO 3 /H-diamane, and ReO 3 /H-diamane near the Fermi level, and the magnetic moments are mainly from the adsorbed molecules, which likely originates from transferred electrons into the molecules. Such spin splitting has been observed in TCNQ-doped graphene, graphene quantum dots, CrO 3 - V 2 O 5 -doped H-terminated diamond surfaces, and MoO 3 -doped BN (100) surfaces . Excitingly, for all systems, the surface acceptors are efficient to drive the Fermi level below the VBM of H-diamane, and H-diamane becomes degenerate.…”

“…12,13 The stability of diamane is improved by B dopants; 14 B and N dopants reduce the formation energy to promote its synthesis. 15 Besides, surface transfer doping is a simple and effective method to modulate the surface conductivity and electronic structures, 16,17 which is first proposed to explain the surface conductivity of H-terminated diamond, 18 and it has been successfully applied to several materials, such as diamond, 19 c-BN, 20,21 MoS 2 monolayer, 22 and phosphorene. 23 The Hterminated diamond has a negative electron affinity, 24 which favors electrons to escape from the surface.…”

Chemical approaches for electronic doping in photovoltaic materials beyond crystalline silicon

“…Transition metal oxides, such as MoO 3 , was a widely used p-dopant due to their deep-lying electronic energy states. 267,268 With 64 Å of the n-type MoO 3 (E A of about 6.7 eV) deposited upon MAPbI 3 , the energy levels of MoO 3 shifted toward a lower binding energy by 0.30 eV, while the energy levels of MAPbI 3 shifted toward a higher binding energy by 0.25 eV, indicating the electron transfer from MAPbI 3 to MoO 3 . 269 Mo 4+ and Mo 5+ oxidation states, with 3d 5/2 binding energies at 230.1 eV and 232.0 eV respectively, appear in the XPS core level spectrum, revealing that a chemical reaction takes place at the perovskite/ MoO 3 interface.…”