Characteristics of p-Type Conduction in P-Doped MoS2 by Phosphorous Pentoxide during Chemical Vapor Deposition

Abstract

We demonstrated p-type conduction in MoS₂ grown with phosphorous pentoxide via chemical vapor deposition (CVD). Monolayer MoS₂ with a triangular shape and 15-µm grains was confirmed by atomic force microscopy. The difference between the Raman signals of the A_1g and E¹_2g modes for both the pristine and P-doped samples was 19.4 cm^-1. In the X-ray photoelectron spectroscopy results, the main core level peaks of P-doped MoS₂ downshifted by about 0.5 eV to a lower binding energy compared to the pristine material. Field-effect transistors (FETs) fabricated with the P-doped monolayer MoS₂ showed p-type conduction with a field-effect mobility of 0.023 cm²/V⋅s and an on/off current ratio of 10³, while FETs with the pristine MoS₂ showed n-type behavior with a field-effect mobility of 29.7 cm²/V⋅s and an on/off current ratio of 10⁵. The carriers in the FET channel were identified as holes with a concentration of 1.01 × 10¹¹ cm^-2 in P-doped MoS₂, while the pristine material had an electron concentration of 6.47 × 10¹¹ cm^-2.

Keywords: P-doped MoS2; P2O5; chemical vapor deposition; p-type conduction.