A quantum dot is a nanometer-sized object (usually a semiconductor), where excitons are confi ned in all three spacial dimensions. GQDs are graphene fragments that are small enough tocause exciton confi nement and a quantum size effect. Typically,GQDs have diameters below 20 nm. Inorganic semiconductor quantum dots (QDs) have attracteda huge amount of interest over the past two decades, owingto their unusual and interesting optical and electronic properties.[19] The main disadvantages of colloidal semiconductorQDs include their sometimes intrinsic toxicity (for example inthe case of the very popular CdSe QDs) and the fact that theyare colloids, which makes coupling of chemicals diffi cult andcauses problems with the colloidal stability in many applications. As GQDs have more “molecule-like” character, they aremuch easier to handle compared to colloidal QDs, are non-toxicand show the desirable electro-optic properties of quantum dots.
đang được dịch, vui lòng đợi..