| Abstract [eng] |
Nowadays, the use of organic materials in electronic devices is one of the main topic. One of the most promising application area for organic materials is bulk heterojunction Solar cells. The aim of this work was to find a bimolecular recombination coefficient and its reduction factor in P3HT:PCBM bulk heterojunction Solar cells, and compare it to other bulk heterojunction Solar cells structures; and to develop a charge blocking layers for bulk heterojunction Solar cells and characterize them. In this work mixtures of new hole transport materials V1353 and V1390 (synthesized in KTU, prof. V. Getautis group) with electron transport material ST917 (Samsung) are investigated. The values of drift mobilities and bimolecular recombination were compared with those obtained in PCBM:P3HT bulk heterojunction. In ST917:V1353 and ST917:V1390 bulk heterojunctions - drift mobilities and bimolecular recombinations are significantly lower than in PCBM:P3HT - ST917:V1353 and ST917:V1390 are not suitable for bulk heterojunctions Solar cells. By using I-CELIV method the recombination velocity v in PCBM:P3HT were measured and compared with a bimolecular recombination 𝛽 in bulk heterojunction PCBM:P3HT structures. A higher recombination velocity corresponds to a higher bimolecular recombination coefficient. The recombination velocity depends on extracted charge as v ~ Qn , where n is between 1.4 and 1.8, such dependence could be explained by 2D Langevin recombination. |
