Enhancement of the Photoelectric Performance of (6,5) Carbon Nanotubes via Construction of Type‐I Heterojunctions with Rhodamine B

ABSTRACT Precise structural design and controllable fabrication of single‐wall carbon nanotube (SWCNT) heterojunctions are key to harnessing their optoelectronic performance and advancing high‐performance optoelectronic devices. Here, we integrated Rhodamine B (RhB) molecules into (6,5) SWCNT films via a simple immersion method, thereby forming a Type I heterojunction. A dual enhancement of photoluminescence (PL) and photoelectric conversion efficiency was experimentally observed for the first time in Type I heterojunction films, with external PL efficiency increasing by more than two‐fold and photoelectric conversion efficiency improving by approximately one order of magnitude. These enhancements are attributed to the strong π–π stacking interactions between RhB and (6,5) SWCNTs, as well as the favorable matching of their absorption bands, which facilitates efficient exciton energy transfer from RhB to SWCNTs and substantially increases exciton density in the (6,5) SWCNT films. Additionally, under illumination, the photoinduced electron transfer from RhB to SWCNTs results in the accumulation of positive charges within the RhB layer, triggering the photogating effect and further enhancing the photoconductivity gain. The findings provide new insights into exciton and electron transfer processes in Type‐I heterojunctions for enhancing the photoelectric performance of SWCNT films, offering guidance for the design of high‐performance photoelectric devices.