Large Area Vertically Oriented Few-Layer MoS for Efficient Thermal Conduction and Optoelectronic Applications.

Large area growth of MoS can show great advances in optoelectronic devices due to its unique optical and electronic properties. Here, we directly grow vertically oriented and interconnected few-layer MoS over 1 × 1 cm of p-type Si substrate using CVD technique. We report for the first time the thermal conductivity of vertically oriented few-layer (VFL) MoS using the optothermal Raman technique. The reduced phonon-defect scattering due to minimal defects and strains in VFL MoS results in excellent thermal conductivity of 100 ± 14 W m K at room temperature. The photoluminescence and DFT study confirm the semiconducting behavior of VFL-MoS. The VFL-MoS/Si photodiode shows high photoresponsivity of 7.37 A W at -2.0 V bias under 0.15 mW cm intensity of 532 nm laser. The enhanced light trapping and highly exposed edges of VFL MoS due to vertical orientation, formation of efficient p-n junction at the MoS/Si interface and effective charge separation leads to the excellent performance of grown VFL-MoS for optoelectronic applications.