Jongdeok An

Improvement in power conversion efficiency by blending of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) into poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester active layer

The improvement in power conversion efficiency (PCE) by the addition of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) into regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM)-based bulk heterojunction (BHJ) organic photovoltaic (OPV) devices was investigated. The addition of PEDOT:PSS into the P3HT:PCBM active layer was found to promote a significant enhancement of the fill factor, which ultimately increased the PCEs of the corresponding OPV devices, although the exciton generation rates of the BHJ layers were virtually the same, as observed by UV-Vis absorption spectra. Therefore, we conclude that the reduction of internal series resistance (RS) was the most crucial reason for the PCE improvement by the addition of PEDOT:PSS.

Exciton Dynamics of P3HT:PCBM Blend Films with Different Polymer Regioregularities Using Transient Absorption Spectroscopy

The poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) blending is one of the most intensively studied active material systems for bulk-heterojunction (BHJ) organic photovoltaic devices. For the active layer with BHJ structure, the charge tranfer (CT) and exciton dissociation processes between P3HT and PCBM are the important initial steps to form free charge carriers in the active layer. To compare the CT related species from the transient absorption dynamics in P3HT:PCBM blend systems with different orderings of the polymer, we investigated the charge carrier dynamics in P3HT:PCBM blend films with regiorandom and regioregular polymer structures using femtosecond transient absorption spectroscopy.

Correction: Light-penetration and light-scattering effects in dye-sensitised solar cells

Correction for ‘Light-penetration and light-scattering effects in dye-sensitised solar cells’ by Kyung-Jun Hwang et al., New J. Chem., 2014, 38, 6161–6167.