DPhotovoltaic and Polarization Effect in Strain‐Engineering 2H‐MoTe ₂ Lateral Homojunction

Doping lays the foundation for the realization of diverse functions of semiconductor devices. In layered two‐dimensional (2D) semiconductors, nevertheless, polarity mediation doping is still a major obstacle. To overcome these limitations and fully exploit the unique advantages of atomic‐scale thickness and high elasticity of 2D semiconductors, strain engineering has emerged as an effective route. Herein, lateral homojunctions are constructed in 2H‐MoTe 2 by strain engineering showing a typical photovoltaic (PV) response. Polarization responses with polarization ratios of 2.09 at 830 nm and 1.09 at 1550 nm are realized in 2H‐MoTe 2 lateral homojunctions absent in the photoconductive (PC) devices, which is closely correlated to the strain‐induced reduction in crystal symmetry revealed by the angle‐resolved polarized Raman technique. Broad detection from 520 nm to 1550 nm is illustrated both in the PC and PV devices. Peak responsivity ( R ), detectivity ( D *) and external quantum efficiency ( EQE ) arrive at 7.5 A/W, 1.2 × 10 11 Jones and 2.7 × 10 3 % at 520 nm illumination for the PV detector with a far lower response time of 25 µs than 375 µs for the PC one. This work highlights the potential of the strain engineering for advancing 2D material diverse functions of the electronics and optoelectronics devices.