The particle size of nitrogen-doped carbon quantum dots (NCQDs) can have an impact on their electrical conductivity, as it can affect their charge transport properties.

Generally, smaller NCQDs have a higher surface area to volume ratio, which can result in a higher density of surface states that are available for charge transport. This can lead to enhanced electrical conductivity in smaller NCQDs compared to larger ones.

Moreover, smaller NCQDs can exhibit quantum confinement effects, where the electronic states are confined in all three dimensions, leading to discrete energy levels and altered charge transport properties. This can also contribute to the enhanced electrical conductivity observed in smaller NCQDs.

However, the exact relationship between NCQD particle size and electrical conductivity may depend on the specific synthesis method used and the doping concentration of nitrogen, among other factors. Therefore, more detailed studies are needed to fully understand the relationship between NCQD particle size and electrical conductivity.