Influence of extraction barrier on the loss process of photogenerated charge carrier in polymer bulk heterojunction solar cells

• Published in: Chemical research in Chinese universities Vol. 31; no. 5; pp. 809 - 813
• Main Authors: Liu, Bo, Xu, Feng, Zhang, Xinghua, Yan, Dadong, Lu, Dan
• Format: Journal Article
• Language: English
• Published: Changchun Jilin University and The Editorial Department of Chemical Research in Chinese Universities 01-10-2015; State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry,Jilin University, Changchun 130012, P.R.China%Department of Chemistry, Tsinghua University, Beijing 100084, P.R.China%School of Science, Beijing Jiaotong University, Beijing 100044, P.R.China%Department of Physics, Beijing Normal University, Beijing 100875, P.R.China
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Inorganic Chemistry; Organic Chemistry; Physical Chemistry; Charge collection efficiency; Extraction/injection barrier; Polymer solar cell; Master eqution
• ISSN: 1005-9040; 2210-3171
• DOI: 10.1007/s40242-015-5102-6

Based on a full device model adopting three-dimensional Pauli master equation approach, the charge carrier loss process due to poor extraction channels between electrode and active layer in polymer bulk heterojunction( BHJ) solar cells was studied. The influence of barrier height on device performance was simulated to reveal the importance of electrode improvement. It was found that relatively large extraction barrier height(over 0.40 eV) can lead to the significant diminishing of the overall charge collection efficiency, since bimolecular recombination rate would increase to a high level due to enhanced space charge accumulation effect near electrodes. In contrast, the percentage of charge carrier annihilated due to geminate recombination did not change significantly with barrier height variation. Our simulation results may provide the basis for a more accurate model and potential direction of polymer BHJ solar cells improvement.