另外我們通過稀釋不同倍率的摻雜0.77 mM、2.31 mM、7.71 mM二硫化鉬量子點,觀測到其螢光強度有增強的趨勢,稀釋75倍到達原本強度的800倍,推測是濃度越高會導致激子交互作用,並且能量轉移,讓發光強度變弱並且吸收上升,再藉由光激螢光激發光譜發現經由稀釋作用的摻雜二乙烯三胺二硫化鉬量子點會有所謂的峰值分裂的現象,隨著濃度的增加其分裂的會越來越分開其分裂差竟然可以高達900 meV,進一步討論其推測可能是激子與激子耦合 (exciton-exciton coupling) 的影響,不同排列方式的偶極矩耦合導致能量不同,光激螢光激發光譜中才會有分裂的情形發生,而在吸收方面我們發現,隨著濃度上升,二硫化鉬量子點能隙會有紅位移的現象發生。
We successfully use a simple and fast top-down method for the synthesis of MoS2 Quantum Dots (QDs) from molybdenum disulfide (MoS2) powder in ethanol (ETOH) by pulsed laser ablation. Concurrently, diethylenetriamine (DETA) is added as a dopant to enhance the photoluminescence intensity of MoS2 QDs. To understand more of the MoS2 QDs structure, the Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used. The measurements of particle size and elemental analysis of DETA doped MoS2 QDs confirmed the success of DETA doping on the MoS2 QDs. At DETA doping concentration of 0.77 mM, the doped MoS2 QDs displays the highest PL intensity with roughly 190 fold higher than the undoped sample.