Horizontal transfer of aligned Si nanowire arrays and their photoconductive performance

An easy and low-cost method to transfer large-scale horizontally aligned Si nanowires onto a substrate is reported. Si nanowires prepared by metal-assisted chemical etching were assembled and anchored to fabricate multiwire photoconductive devices with standard Si technology. Scanning electron microscopy images showed highly aligned and successfully anchored Si nanowires. Current-voltage tests showed an approximately twofold change in conductivity between the devices in dark and under laser irradiation. Fully reversible light switching ON/OFF response was also achieved with an I_ON/I_OFF ratio of 230. Dynamic response measurement showed a fast switching feature with response and recovery times of 10.96 and 19.26 ms, respectively.