In this study, we explored the potential of carbon nanotubes (CNTs) for enhancing n-type thermoelectric properties. The unique quantum confinement effect in one-dimensional nanowires like CNTs, decouples the thermoelectric parameters of Seebeck coefficient and electrical conductivity. We studied CNT composite thin films using a combination of a polymeric dopant (PEI) and a cationic surfactant (DODMAC), which played distinctive roles within the composite material. PEI facilitated active electron donation by covalently grafting onto CNTs, resulting in increased carrier concentration and enhanced electrical conductivity. Moreover, high PEI content led to the crosslinking between CNTs, forming a clustered mesostructure that promoted intertube electron transport via band conduction. In contrast, DODMAC functionalization reduced the van der Waals contacts between neighboring CNTs, and strong localization limited electron transport mainly through electron hopping within DODMAC-CNT systems. While DODMAC exhibited limited roles in improving electrical conductivity, it demonstrated high potential for maintaining long-term stability of n-type CNTs by preventing oxidation and volatilization of PEI dopants.