Chemical Doping Effects in Multilayer MoS₂ and Its Application in Complementary Inverter

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanoscience

Background:

• Multilayer molybdenum disulfide (MoS₂) shows promise for flexible electronics, but suffers from performance limitations due to Schottky barriers and defects.
• Developing strategies to overcome these limitations is crucial for realizing the full potential of MoS₂ in advanced electronic devices.

Purpose of the Study:

• To investigate the effects of poly(diketopyrrolopyrrole-terthiophene) (PDPP3T) doping on the electrical characteristics of multilayer MoS₂.
• To elucidate the underlying mechanisms responsible for the observed performance enhancements using advanced characterization techniques.

Main Methods:

• Doping of multilayer MoS₂ with PDPP3T.
• Electrical characterization of doped MoS₂ devices.
• Synchrotron-based X-ray photoelectron spectroscopy (XPS) and grazing incidence wide-angle X-ray diffraction (GWAXD) to study material structure and interactions.

Main Results:

• PDPP3T doping resulted in significantly improved electrical characteristics, including an approximately 4.6-fold increase in on-current and a high current on/off ratio of 10⁶.
• Synchrotron studies revealed that PDPP3T crystallites align edge-on (97.5%) with MoS₂, leading to enhanced interaction, dipole formation, and charge transfer at an annealing temperature of 300 °C.
• Demonstration of a functional complementary metal-oxide-semiconductor inverter utilizing PDPP3T-doped MoS₂.

Conclusions:

• PDPP3T doping is an effective strategy to overcome performance limitations in multilayer MoS₂ devices.
• The enhanced electrical properties are attributed to improved crystallite alignment, dipole formation, and charge transfer between PDPP3T and MoS₂.
• The findings pave the way for high-performance flexible electronic devices, including advanced inverters.