Abstract
Multiwall carbon nanotube (MWCNT) fibrils were introduced into TiO~2–x~N__~x~__ photoelectrodes to enhance charge collection efficiency as charge‐transport pathways. For comparison, we also synthesized MWCNT/TiO~2~ nanocomposites to fabricate dye‐sensitized solar cells (DSCs). The effect of MWCNTs on the photovoltaic performance of the DSCs was studied in detail. The performance of DSCs based on MWCNT/TiO~2–x~N__~x~__ differs significantly from that of MWCNT/TiO~2~ photoelectrodes. A high energy conversion efficiency of 7.66 % was achieved in the dye‐sensitized MWCNT/TiO~2~ nanocomposites solar cells. The results show that remarkable enhancement of ca. 33 % and ca. 40 % in the conversion efficiency (η) and short‐circuit photocurrent density (J~sc~), respectively, occurrs for the DSCs based on MWCNT/TiO~2~ than those made of pure TiO~2~ electrodes. The energy conversion efficiency of DSCs based on TiO~2–x~N__~x~__ electrodes was 6.98 %, which is similar to that of MWCNT/TiO~2–x~N__~x~__ DSCs (6.88 %–5.17 %). We also investigated the charge collection efficiency, electron transport, electron lifetime, and photocurrent transient behavior by electrochemical analysis. The introduced MWCNTs exhibit a smaller sheet resistance and electron transfer resistance, as well as a longer electron lifetime. A 20 % enhancement in the charge collection efficiency is achieved in the nanocomposite DSCs.