*** Corresponding author. .

As the key to manufacturing large scale integrated circuits, horizontally aligned semiconducting single-walled carbon nanotube (s-SWNT) arrays play a key role in the next-generation electronic device. Though various techniques have been developed, obtaining pure s-SWNT horizontal arrays is still the greatest challenge. Here, we propose an effective and facile method to produce s-SWNT arrays from a diverse perspective by implementing photochemical chlorination on the as-grown aligned SWNT arrays. The electrical measurements demonstrate a high fraction of s-SWNTs (>98.1%) after photochlorination, and its exceptional performance as a field-effect transistor with an on-off ratio up to 3730. Meanwhile, through the well-controlled mask-assisted photo-chlorination, a type of metallic-semiconducting SWNT intramolecular junction with rectifying diode and non-linear transport characteristics has also been successfully obtain. Our work provides a new method for the preparation of high-purity s-SWNT arrays and SWNT intramolecular junction, which has great significance for the carbon-based nano-electronic devices in applications.