(A) study on the characteristics of charge extraction at the electron transport layer/active layer interfaces for improving the performance of hybrid solar cells

Abstract

Although the colloidal quantum dot (CQD)/organic hybrid solar cell has been considered very attractive for emerging photovoltaic devices, further improvements of charge extraction properties at electron transport layer (ETL)/CQD interfaces should be proposed for realizing the full potential in the CQD/organic hybrid. Hence, we carefully adjust the interface properties between zinc oxide (ZnO) as ETL and CQD layer by introducing an interfacial layer (IL). The IL having the energy band which is located in the center between ZnO and CQD layer, suppresses the local charge accumulation, thereby reducing the bimolecular recombination at ZnO/CQD interfaces

an optimal IL creates a complete energy band bending and prevent the formation of shallow traps, resulting in improved performance of CQD/organic hybrid. Finally, a CQD/organic hybrid solar cell exhibits a maximum power conversion efficiency (PCE) of 14.01 %, and superior stability retaining more than 80 % of its initial performance even after 300 hours under the maximum power point (MPP) condition.