Single-crystalline germanium nanomembrane photodetectors on foreign nanocavities
Journal
Science Advanced
Journal Volume
3
Journal Issue
7
Date Issued
2017
Author(s)
Zhenyang Xia
Haomin Song
Munho Kim
Ming Zhou,
Dong Liu
Xin Yin
Kanglin Xiong
Hongyi Mi
Xudong Wang
Fengnian Xia
Zongfu Yu
Zhenqiang Jack Ma
Qiaoqiang Gan
Abstract
Miniaturization of optoelectronic devices offers tremendous performance gain. As the volume of photoactive material decreases, optoelectronic performance improves, including the operation speed, the signal-to-noise ratio, and the internal quantum efficiency. Over the past decades, researchers have managed to reduce the volume of photoactive materials in solar cells and photodetectors by orders of magnitude. However, two issues arise when one continues to thin down the photoactive layers to the nanometer scale (for example, <50 nm). First, light-matter interaction becomes weak, resulting in incomplete photon absorption and low quantum efficiency. Second, it is difficult to obtain ultrathin materials with single-crystalline quality. We introduce a method to overcome these two challenges simultaneously. It uses conventional bulk semiconductor wafers, such as Si, Ge, and GaAs, to realize single-crystalline films on foreign substrates that are designed for enhanced light-matter interaction. We use a high-yield and high-throughput method to demonstrate nanometer-thin photodetectors with significantly enhanced light absorption based on nanocavity interference mechanism. These single-crystalline nanomembrane photodetectors also exhibit unique optoelectronic properties, such as the strong field effect and spectral selectivity. Copyright © 2017 The Authors, some rights reserved.
Other Subjects
Crystalline materials; Efficiency; Electromagnetic wave absorption; Gallium arsenide; Germanium; III-V semiconductors; Light absorption; Nanostructures; Optoelectronic devices; Photodetectors; Photons; Semiconducting gallium arsenide; Semiconducting silicon; Signal to noise ratio; Silicon wafers; Substrates; Enhanced light absorptions; High-throughput method; Interference mechanisms; Internal quantum efficiency; Light-matter interactions; Optoelectronic properties; Single crystalline quality; Single-crystalline film; Quantum efficiency
Type
journal article