Rapid thermal-treated transparent conductor on microscale Si-pillars for photoelectric applications

•RTP process significantly improves ITO film quality.•Pillar structured Si efficiently enlarges the surface area.•ITO/Si-pillar heterojunction effectively controls current values.•This demonstrates an efficient approach for high-performing photoelectric devices.

Various silicon (Si)-pillars were designed to modulate surficial lengths for high-performing photodetectors. An electrically conductive and optically transparent indium-tin-oxide (ITO) was coated on Si-pillars to form heterojunction devices. A rapid thermal treatment significantly improves the transparency of an ITO film with a better crystal nature. Si-pillar structures are effective to reduce light-reflection and spontaneously increase Si surficial lengths. An enhanced light-reactive Si surface simultaneously enhances the photo-responses. We found that pillar designs are also efficient to suppress a leakage current. This demonstrates an efficient approach for high-performing photoelectric devices at a low thermal budget.