Temperature-dependent piezotronic effect of MoS2 monolayer

Molybdenum disulfide (MoS2) monolayer is one of the most promising materials for next-generation electronic/optoelectronic devices because of its prominent piezoelectric property that can modulate Schottky barrier height and control transport behaviors without applying any external gate bias. In this work, we systematically investigated temperature dependence of piezotronic effect of chemical vapor deposition grown MoS2 monolayer by measuring transport behaviors under strains from 0% to 0.3% with various sample temperatures ranging from 270 K to 320 K. It was found that piezoelectric effect in MoS2 monolayer significantly depends on sample temperature. Due to less screening effect of piezoelectric potential generated in MoS2 with a mechanical strain at low temperature, the piezotronic effect is significantly enhanced when the sample temperature is decreased from 320 K to 270 K, revealing that the piezoelectric effect becomes stronger at lower temperature.