In this paper, we report a study on the optical and the electrical properties of pure cotton ?bers (CF) from chemically surface- and morphology-modi?ed samples coated with poly [2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) polymer by using a dip-coating method. The performance of ?bers with MEH-PPV polymer as a coating component was investigated, and an excellent white-light emission that consisted of blue-, green-, and red-light-emitting bands was demonstrated. The I-V characteristics of sandwich-type devices consisting of successive layers of ITO (Indium doped tin oxide coated glass)-PEDOT-PSS (Poly (3,4-ethylenedioxythiophene)-Poly(styrenesulfonate)-CF/MEH-PPV-Ag showed that up on light illumination, the current increased in both the forward and the reverse bias conditions which suggest that the photo response parameters for the heterojunction are better than they are for the composite alone