Interface Engineering to Enhance the Photoresponse of Core-Shell Structure Silicon Nanowire Photodetectors

The core-shell silicon nanowire photodetector has been reported with enhanced responsivity. The interface traps play critical role to determine the performance of core-shell photodetector. The effect of interface quality on the photo response has been investigated using crystalline silicon and polysilicon shells. The device with single-crystalline silicon shell exhibits higher responsivity than that with polysilicon shell. The performance degradation of polysilicon device is caused by the grain boundaries, which are defect sources. Based on these results, the single-crystalline silicon shell was used for fabricating core-shell silicon nanowire photodetector. The photodetector exhibits the maximum responsivity of 0.51 A/W, which is 10% higher than the planar photodetector. Consequently, the core-shell homogeneous silicon nanowire structure can be a promising component for photodetector application.