Efficient three-dimensional nanostructured photoelectric device by Al-ZnO coating on lithography-free patterned Si nanopillars

Abstract

An efficient three-dimensional (3D) nanostructure photoelectric device is presented. An Al-doped ZnO (AZO) coating was applied to lithography-free patterned Si nanopillars and spontaneously formed a radial heterojunction (n-AZO/p-Si) photodiode having a quality ideality factor of 1.64. A significantly enhanced photocurrent of 5.45 mA/cm2 was obtained from the 3D nanostructure relative to that of a planar substrate (1.1 mA/cm2). This enhancement is induced by enlargement of the light-active surface area and an anti-reflection effect. Due to the intermediate refractive index of AZO, the reflection was distinctively reduced in the air-Si system. It discusses an effective approach for realizing nanostructured photoelectric device.