Realizing High-Efficiency Omnidirectional n‑Type Si Solar Cells via the Hierarchical Architecture Concept with Radial Junctions

• Published in: ACS nano Vol. 7; no. 10; pp. 9325 - 9335
• Main Authors: Wang, Hsin-Ping, Lin, Tzu-Yin, Hsu, Chia-Wei, Tsai, Meng-Lin, Huang, Chih-Hsiung, Wei, Wan-Rou, Huang, Ming-Yi, Chien, Yi-Jiunn, Yang, Po-Chuan, Liu, Chee-Wee, Chou, Li-Jen, He, Jr-Hau
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 22.10.2013
• Subjects: Architecture; Carriers; Czochralski process; Mass production; Nanostructure; Photovoltaic cells; Separation; Silicon substrates; Solar cells; photon management; Si heterojunction (SHJ) solar cells; omnidirectional; high-efficiency; chemical polishing etching; hierarchical architecture; radial junctions
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn404015y

Hierarchical structures combining micropyramids and nanowires with appropriate control of surface carrier recombination represent a class of architectures for radial p-n junction solar cells that synergizes the advantageous features including excellent broad-band, omnidirectional light-harvesting and efficient separation/collection of photoexcited carriers. The heterojunction solar cells fabricated with hierarchical structures exhibit the efficiency of 15.14% using cost-effective as-cut Czochralski n-type Si substrates, which is the highest reported efficiency among all n-type Si nanostructured solar cells. We also demonstrate the omnidirectional solar cell that exhibits the daily generated power enhancement of 44.2% by using hierarchical structures, as compared to conventional micropyramid control cells. The concurrent improvement in optical and electrical properties for realizing high-efficiency omnidirectional solar cells using as-cut Czochralski n-type Si substrates demonstrated here makes a hierarchical architecture concept promising for large-area and cost-effective mass production.