Abstract

A practical technique for determining the length of a silicon nanowire (SiNW) array is reported by the analysis of reflected images from a smartphone camera. The SiNW array was prepared by electroless chemical etching and its length controlled by the etching time of a Si wafer. The average lengths for the SiNW array were characterized by scanning electron microscopy. The relationship between the reflection spectrum and the length of the SiNW array was investigated. The ratio of percent reflectance from 900 to 550 nm exponentially increased from 1.8 ± 0.1 to 22.2 ± 1.3 when the average length increased from 184 ± 12 to 1237 ± 23 nm. Optical sensing for characterization of the length of SiNW was further developed into a simple and practical technique using a smartphone camera as a detector. A 3D printed tool was assembled to the smartphone to control the light path and the reflected image of the SiNW array was acquired. The reflected intensity ratio obtained from the reflected images with long pass to short pass filters increased analogously to the spectroscopic results. This optical-sensing-based smartphone showed simple and rapid detection for determining the lengths of a SiNW array and a SiNW array coated with a polymer film. This platform is compact and capable of on-site detecting and is promising for the characterization of reflective materials.

摘要

通过分析智能手机相机的反射图像，报告了一种用于确定硅纳米线 (SiNW) 阵列长度的实用技术。SiNW 阵列是通过化学蚀刻制备的，其长度由 Si 晶片的蚀刻时间控制。SiNW 阵列的平均长度通过扫描电子显微镜表征。研究了反射光谱与SiNW阵列长度之间的关系。当平均长度从 184 ± 12 增加到 1237 ± 23 nm 时，900 到 550 nm 的反射率百分比从 1.8 ± 0.1 成指数增加到 22.2 ± 1.3。用于表征 SiNW 长度的光学传感进一步发展成为一种简单实用的技术，使用智能手机相机作为检测器。将 3D 打印工具组装到智能手机上以控制光路并获取 SiNW 阵列的反射图像。从具有长通到短通滤波器的反射图像获得的反射强度比与光谱结果类似地增加。这种基于光学传感的智能手机显示出简单而快速的检测，可用于确定 SiNW 阵列和涂有聚合物薄膜的 SiNW 阵列的长度。该平台结构紧凑，能够进行现场检测，有望用于反射材料的表征。这种基于光学传感的智能手机显示出简单而快速的检测，可用于确定 SiNW 阵列和涂有聚合物薄膜的 SiNW 阵列的长度。该平台结构紧凑，能够进行现场检测，有望用于反射材料的表征。这种基于光学传感的智能手机显示出简单而快速的检测，可用于确定 SiNW 阵列和涂有聚合物薄膜的 SiNW 阵列的长度。该平台结构紧凑，能够进行现场检测，有望用于反射材料的表征。