|標題:||P-Type Doping of WS2 Quantum Dots via Pulsed Laser Ablation|
|作者:||Caigas, Septem P.|
Santiago, Svette Reina Merden S.
Department of Electrophysics
|關鍵字:||WS2 quantum dot;doping;photoluminescence;conductivity;pulsed laser ablation|
|摘要:||Doping provides an advantage to engineering the optical and electrical characteristics of transition-metal dichalcogenides (TMDs). Here, we report the doping of WS2 quantum dots (QDs) with diethylenetriamine (DETA) using pulsed laser ablation. The synthesized DETA-doped 2H-WS2 QDs with an average size of similar to 6 nm have been demonstrated by transmission electron microscopy. With the introduction of DETA during pulsed laser ablation, current modulation, carrier concentration, and field-effect mobility are greatly enhanced, demonstrating a successful doping in WS2 QDs. The positive shift of the threshold voltage in gate dependent conductance measurements reveals p-type doping for DETA-doped WS2 QDs. A remarkable improvement in photoluminescence in WS2 QDs by 74-fold has been achieved after DETA doping. An anomalous dopant-dependent negative photoconductivity was observed for WS2 QDs, originating from light-induced desorbing of water (oxygen) molecules on the surface. The proposed doping approach can provide a vehicle to modulate the optical and electrical properties in WS2 QDs and could be important in the performance improvement of WS2-QD-based devices.|
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