title: Large-Area Nanosphere Self-Assembly by a Micro-Propulsive Injection Method for High Throughput Periodic Surface Nanotexturing.
abstract: A high throughput surface texturing process for optical and optoelectric devices based on a large-area self-assembly of nanospheres via a low-cost micropropulsive injection (MPI) method is presented. The novel MPI process enables the formation of a well-organized monolayer of hexagonally arranged nanosphere arrays (NAs) with tunable periodicity directly on the water surface, which is then transferred onto the preset substrates. This process can readily reach a throughput of 3000 wafers/h, which is compatible with the high volume photovoltaic manufacturing, thereby presenting a highly versatile platform for the fabrication of periodic nanotexturing on device surfaces. Specifically, a double-sided grating texturing with top-sided nanopencils and bottom-sided inverted-nanopyramids is realized in a thin film of crystalline silicon (28 μm in thickness) using chemical etching on the mask of NAs to significantly enhance antireflection and light trapping, resulting in absorptions nearly approaching the Lambertian limit over a broad wavelength range of 375-1000 nm and even surpassing this limit beyond 1000 nm. In addition, it is demonstrated that the NAs can serve as templates for replicas of three-dimensional conformal amorphous silicon films with significantly enhanced light harvesting. The MPI induced self-assembly process may provide a universal and cost-effective solution for boosting light utilization, a problem of crucial importance for ultrathin solar cells.
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.
authors.forename: Pingqi
authors.initials: P
authors.lastname: Gao
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.
authors.forename: Suqiong
authors.initials: S
authors.lastname: Zhou
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.|‡Department of Physics, Nanchang University, Nanchang, 330047, People's Republic of China.
authors.forename: Sizhong
authors.initials: S
authors.lastname: Li
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Sheng
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: ‡Department of Physics, Nanchang University, Nanchang, 330047, People's Republic of China.
authors.forename: Tianbao
authors.initials: T
authors.lastname: Yu
authors.affiliation: †Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, People's Republic of China.
authors.forename: Jichun
authors.initials: J
authors.lastname: Ye
authors.affiliation: §Department of Material Science and Engineering, Stanford University, Stanford, California 94305, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
keywords: Self-assembly; light-trapping; microsphere lithography; nanofabrication; photovoltaic