title: Spontaneous formation of light-trapping nano-structures for top-illumination organic solar cells.
abstract: By introduction of nano-structured crystallite capping layers, the power conversion efficiency of top-illumination organic solar cells is improved from 4.2 ± 0.1% to 6.0 ± 0.2%, representing a 44% enhancement. This is caused by the increase in JSC and led by the enhancement in the local E distribution inside the active layers. Comprehensive finite-difference time domain simulation reveals two main reasons for this enhancement: (1) the nano-structured capping layers can be treated as gradient-index films that effectively increase the light entering the devices. (2) The nano-structured capping layers can also diffract the light from original normal-incident paths, hence increasing the absorption length inside the active layers.
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan. hwlin@mx.nthu.edu.tw.
authors.forename: Zheng-Yu
authors.initials: ZY
authors.lastname: Huang
authors.forename: Si-Wen
authors.initials: SW
authors.lastname: Chiu
authors.forename: Chang-Wen
authors.initials: CW
authors.lastname: Chen
authors.forename: Yi-Hong
authors.initials: YH
authors.lastname: Chen
authors.forename: Li-Yen
authors.initials: LY
authors.lastname: Lin
authors.forename: Ken-Tsung
authors.initials: KT
authors.lastname: Wong
authors.forename: Hao-Wu
authors.initials: HW
authors.lastname: Lin
mesh_terms: D049329:Nanostructures / Q000737:chemistry*; D009281:Naphthalenes / Q000737:chemistry*; D010618:Phenanthrolines / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D009281:Naphthalenes; D010618:Phenanthrolines; C002850:4,7-diphenylphenanthroline sulfonate