Most doping research into transition metal dichalcogenides (TMDs) has been mainly focused on the improvement of electronic device performance. Here, the effect of self-assembled monolayer (SAM)-based doping on the performance of WSe2- and MoS2-based transistors and photodetectors is investigated. The achieved doping concentrations are ≈1.4 × 1011 for octadecyltrichlorosilane (OTS) p-doping and ≈1011 for aminopropyltriethoxysilane (APTES) n-doping (nondegenerate). Using this SAM doping technique, the field-effect mobility is increased from 32.58 to 168.9 cm2 V-1 s in OTS/WSe2 transistors and from 28.75 to 142.2 cm2 V-1 s in APTES/MoS2 transistors. For the photodetectors, the responsivity is improved by a factor of ≈28.2 (from 517.2 to 1.45 × 104 A W-1) in the OTS/WSe2 devices and by a factor of ≈26.4 (from 219 to 5.75 × 103 A W-1) in the APTES/MoS2 devices. The enhanced photoresponsivity values are much higher than that of the previously reported TMD photodetectors. The detectivity enhancement is ≈26.6-fold in the OTS/WSe2 devices and ≈24.5-fold in the APTES/MoS2 devices and is caused by the increased photocurrent and maintained dark current after doping. The optoelectronic performance is also investigated with different optical powers and the air-exposure times. This doping study performed on TMD devices will play a significant role for optimizing the performance of future TMD-based electronic/optoelectronic applications.
- device performance
- optoelectronic devices
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials