Organic Light-Emitting Diode Application of Fluorescent Cellulose as a Natural Polymer

Fluorescent cellulose derivatives were synthesized by utilizing the carbazole group in order to induce optical and semi‐conducting properties. The PL spectra of these cellulose derivatives exhibit UV‐blue emissions at about 350–450 nm attributed to carbazole groups. Analyses of photoelectron spectra were also performed to determine IP values. The results of IP, UV‐vis and PL analyses were almost the same as those of PVK, while the PL intensity and efficiency of the cellulose derivatives were quite different. These compounds functioned as hole transporting materials of OLEDs. Devices using each of the derivatives showed different electronic behavior (current density‐voltage characteristics, EL spectra, etc.), indicating the importance of regioselectivity of the substituent group.