Yadav Sushma, Adhikary Buban, Tripathy Puspanjali, Sapra Sameer
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
ACS Omega. 2017 May 22;2(5):2231-2237. doi: 10.1021/acsomega.7b00174. eCollection 2017 May 31.
An efficient and a selective charge extraction from a new type of heterostructured material is demonstrated: the quasi-type-II structure formed upon deposition of ZnSe quantum dots on CdSe nanoplatelets, termed as CdSe/ZnSe dots-on-plates (DoPs) heterostructures. Insights into the charge extraction mechanism are gained from the present studies. Quenching experiments on nanoplatelets (NPLs) and DoPs using electron (benzoquinone) and hole (pyridine) quenchers show the possibility of electron extraction leaving behind the hole in the nanostructures. These outcomes indicate more labile electron extraction in comparison with the hole from these DoP structures vis-à-vis the plate only nanostructures, thereby enabling materials for devices requiring only one type of charges. In CdSe NPLs, the excitons are short-lived making them difficult for various applications involving charge separation. The CdSe/ZnSe DoPs could be alternate candidates for overcoming the difficulties involved with NPLs.
在CdSe纳米片上沉积ZnSe量子点时形成的准II型结构，称为CdSe/ZnSe点在板上（DoPs）异质结构。本研究深入了解了电荷提取机制。使用电子（苯醌）和空穴（吡啶）猝灭剂对纳米片（NPLs）和DoPs进行的猝灭实验表明，电子提取的可能性是在纳米结构中留下空穴。这些结果表明，与仅基于纳米片的纳米结构相比，这些DoP结构中的电子提取比空穴更不稳定，从而使材料适用于仅需要一种电荷类型的器件。在CdSe NPLs中，激子寿命很短，这使得它们难以用于涉及电荷分离的各种应用。CdSe/ZnSe DoPs可能是克服NPLs所涉及困难的替代候选材料。
