Nano-Subsidence Assisted Precise Integration of Patterned Two-Dimensional Materials for High-Performance Photodetector Arrays

TL;DR

This paper introduces a nano-subsidence fabrication method that enables precise integration of patterned 2D materials onto 3D substrates, resulting in high-performance photodetectors with superior sensitivity and efficiency.

Contribution

The study presents a novel nano-subsidence technique for reliable, high-precision integration of 2D materials on non-flat surfaces, advancing silicon photonics integration.

Findings

Devices achieve 0.35 A/W sensitivity

External quantum efficiency of about 90%

Outperforms most commercial photodiodes

Abstract

The spatially precise integration of arrays of micro-patterned two-dimensional (2D) crystals onto three-dimensionally structured Si/SiO$_2$ substrates represents an attractive strategy towards the low-cost system-on-chip integration of extended functions in silicon microelectronics. However, the reliable integration of the arrays of 2D materials on non-flat surfaces has thus far proved extremely challenging due to their poor adhesion to underlying substrates as ruled by weak van der Waals interactions. Here we report on a novel fabrication method based on nano-subsidence which enables the precise and reliable integration of the micro-patterned 2D materials/silicon photodiode arrays exhibiting high uniformity. Our devices display peak sensitivity as high as 0.35 A/W and external quantum efficiency (EQE) of ca. 90%, outperforming most commercial photodiodes. The nano-subsidence technique opens a viable path to on-chip integrate 2D crystals onto silicon for beyond-silicon microelectronics.