Filter-Free Image Sensor Pixels Comprising Silicon Nanowires with Selective Color Absorption

• Published in: Nano letters 2014-04, Vol.14 (4), p.1804-1809
• Main Authors: Park, Hyunsung, Dan, Yaping, Seo, Kwanyong, Yu, Young J, Duane, Peter K, Wober, Munib, Crozier, Kenneth B
• Format: Article
• Language: English
• Subjects: Applied sciences; Color; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; General equipment and techniques; Imaging; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Materials science; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanowires; Photodetectors; Physics; Pixels; Quantum wires; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensors; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Silicon
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl404379w

The organic dye filters of conventional color image sensors achieve the red/green/blue response needed for color imaging, but have disadvantages related to durability, low absorption coefficient, and fabrication complexity. Here, we report a new paradigm for color imaging based on all-silicon nanowire devices and no filters. We fabricate pixels consisting of vertical silicon nanowires with integrated photodetectors, demonstrate that their spectral sensitivities are governed by nanowire radius, and perform color imaging. Our approach is conceptually different from filter-based methods, as absorbed light is converted to photocurrent, ultimately presenting the opportunity for very high photon efficiency.