Generally, p-n junction-based solar energy conversion has the disadvantage of a loss in potential gain in comparison with the photon energy. In this study, we found a more positive potential for a lateral domain interface of p-n junction than for a conventional p-n junction. A terrace bilayer (TB) p-n junction of phthalocyanine (H 2 Pc) and 3,4,9,10perylenetetracarboxylic-bis-benzimidazole (PTCBI) was studied using scanning Kelvin probe microscopy (SKPM), and its electronic properties were analyzed using the contact potential difference (V CPD) data. The analysis of V CPD in the single layer region and the bilayer region (BLR) indicated a vacuum level shift through the electron transfer from PTCBI into indium tin oxide (ITO), from H 2 Pc into ITO and from H 2 Pc into PTCBI. Furthermore, the comparison of these V CPD data indicated a micrometer-localized positive potential in the boundary region (BDR) of the terrace bilayer structure of ptype on n-type. The gain difference of the V CPD reached +0.1 V in comparison with the BLR. The phenomena can be explained as a lateral dipole at the p-n junction. Similar phenomena were observed in TB-H 2 Pc/C 60 /ITO and TB-H 2 Pc/ PTCBI/Au. The gain was extracted as oxidation power in photoelectrochemistry; i.e., at −0.2 V vs. Ag/AgCl a greater anodic current was observed for a patterned terrace bilayer electrode. Additionally, as a photocatalyst film (i.e., a H 2 Pc (dot)/PTCBI/PTFE membrane filter), the p-n dot terrace structure showed a higher quantum efficiency (5.1%) than that of the bilayer (3.2%) for the decomposition of acetic acid. The present design and method were utilized to obtain an efficient photocatalyst, especially through the mitigation of potential loss from the photon energy to redox powers without changing the molecular component.

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A dye-sensitized solar cell (DSSC) fabricated using anthocyanin or chlorophyll natural dye extract coming from Roselle (Hibiscus Sabdariffa) and Green Tea leaves (Camellia Sinensis). Both dye pigmentations were extracted using different alcohol-based solvent, namely, ethanol, methanol and mixed (ethanol + methanol) to identify whether the different solvents give the effect during the dye extraction. The performance of the electron transfer interaction between the natural dye and Titanium Dioxide (TiO2) was determined. The photovoltaic response of DSSC was collected by recording the data of I-V characteristic under illumination. The DSSC using the Roselle dye extract yielded the following results; Voc = 0.001 V, Jsc = 0.00868(mA/cm2), FF = 0.3554 and η = 0.00142% which is coming from the mixed solvent. On the other hand, the green tea dye extract yielded the following results; Voc = 0.3985, Jsc = 0.000797 (mA/cm2), FF = 0.3985 and η = 0.0000752% which is coming from the methanol solvent.