Efficient Charge Extraction from CdSe/ZnSe Dots-on-Plates Nanoheterostructures

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.