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Title: Single-crystalline germanium nanomembrane photodetectors on foreign nanocavities

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. As a result, these single-crystalline nanomembrane photodetectors also exhibit unique optoelectronic properties, such as the strong field effect and spectral selectivity.

Authors:
 [1];  [2];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [3];  [1];  [4];  [2]
  1. Univ. of Wisconsin, Madison, WI (United States)
  2. Univ. at Buffalo, State Univ. of New York, Buffalo, NY (United States)
  3. Yale Univ., New Haven, CT (United States)
  4. (Jack) [Univ. of Wisconsin, Madison, WI (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1369463
Grant/Contract Number:
NA0002915
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Science Advances
Additional Journal Information:
Journal Volume: 3; Journal Issue: 7; Journal ID: ISSN 2375-2548
Publisher:
AAAS
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; photodetector; semiconductor nanomembrane

Citation Formats

Xia, Zhenyang, Song, Haomin, Kim, Munho, Zhou, Ming, Chang, Tzu -Hsuan, Liu, Dong, Yin, Xin, Xiong, Kanglin, Mi, Hongyi, Wang, Xudong, Xia, Fengnian, Yu, Zongfu, Ma, Zhenqiang, and Gan, Qiaoqiang. Single-crystalline germanium nanomembrane photodetectors on foreign nanocavities. United States: N. p., 2017. Web. doi:10.1126/sciadv.1602783.
Xia, Zhenyang, Song, Haomin, Kim, Munho, Zhou, Ming, Chang, Tzu -Hsuan, Liu, Dong, Yin, Xin, Xiong, Kanglin, Mi, Hongyi, Wang, Xudong, Xia, Fengnian, Yu, Zongfu, Ma, Zhenqiang, & Gan, Qiaoqiang. Single-crystalline germanium nanomembrane photodetectors on foreign nanocavities. United States. doi:10.1126/sciadv.1602783.
Xia, Zhenyang, Song, Haomin, Kim, Munho, Zhou, Ming, Chang, Tzu -Hsuan, Liu, Dong, Yin, Xin, Xiong, Kanglin, Mi, Hongyi, Wang, Xudong, Xia, Fengnian, Yu, Zongfu, Ma, Zhenqiang, and Gan, Qiaoqiang. Fri . "Single-crystalline germanium nanomembrane photodetectors on foreign nanocavities". United States. doi:10.1126/sciadv.1602783. https://www.osti.gov/servlets/purl/1369463.
@article{osti_1369463,
title = {Single-crystalline germanium nanomembrane photodetectors on foreign nanocavities},
author = {Xia, Zhenyang and Song, Haomin and Kim, Munho and Zhou, Ming and Chang, Tzu -Hsuan and Liu, Dong and Yin, Xin and Xiong, Kanglin and Mi, Hongyi and Wang, Xudong and Xia, Fengnian and Yu, Zongfu and Ma, Zhenqiang and Gan, Qiaoqiang},
abstractNote = {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. As a result, these single-crystalline nanomembrane photodetectors also exhibit unique optoelectronic properties, such as the strong field effect and spectral selectivity.},
doi = {10.1126/sciadv.1602783},
journal = {Science Advances},
number = 7,
volume = 3,
place = {United States},
year = {Fri Jul 07 00:00:00 EDT 2017},
month = {Fri Jul 07 00:00:00 EDT 2017}
}

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  • High-quality single crystalline Gallium Nitride (GaN) semiconductor has been synthesized using molecule beam epitaxy (MBE) technique for development of high-performance deep ultraviolet (UV) photodetectors. Thickness of the films was estimated by using surface profile meter and scanning electron microscope. Electronic states and elemental composition of the films were obtained using Raman scattering spectroscopy. The orientation, crystal structure and phase purity of the films were examined using a Siemens x-ray diffractometer radiation. The surface microstructure was studied using high resolution scanning electron microscopy (SEM). Two types of metal pairs: Al-Al, Al-Cu or Cu-Cu were used for interdigital electrodes on GaN filmmore » in order to examine the Schottky properties of the GaN based photodetector. The characterizations of the fabricated prototype include the stability, responsivity, response and recovery times. Typical time dependent photoresponsivity by switching different UV light source on and off five times for each 240 seconds at a bias of 2V, respectively, have been obtained. The detector appears to be highly sensitive to various UV wavelengths of light with very stable baseline and repeatability. The obtained photoresponsivity was up to 354 mA/W at the bias 2V. Higher photoresponsivity could be obtained if higher bias was applied but it would unavoidably result in a higher dark current. Thermal effect on the fabricated GaN based prototype was discussed.« less
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  • We demonstrate flexible Ge nanomembrane (Ge NM) based metal-semiconductor-metal photodiodes. The effect of uniaxial tensile strain on Ge NM based photodiodes was investigated using bending fixtures. Dark current density is decreased from 21.5 to 4.8 mA/cm{sup 2} at 3 V by a tensile strain of 0.42% while photon responsivity is increased from 0.2 to 0.45 A/W at the wavelength of 1.5 μm. Enhanced responsivity is also observed at longer wavelengths up to 1.64 μm. The uniaxial tensile strain effectively reduces the direct bandgap energy of the Ge NM, leading to a shift of the absorption edge toward a longer wavelength.
  • Straight single-crystalline Ge nanowires with a uniform diameter distribution of 50-80 nm and lengths up to tens of micrometers were grown in a high yield on sol-gel prepared gold/silica substrates by using Ge powder as the Ge source. Detailed electron microscopy analyses show that the nanowires grow through a vapor-liquid-solid growth mechanism with gold nanoparticles located at the nanowire tips. By using transmission electron microscope grids as the shadow mask, the sol-gel technique can be readily adapted to prepare patterned film-like gold/silica substrates, so that regular micropatterns of Ge nanowires were obtained, which could facilitate the integration of Ge nanowiresmore » for characterization and devices.« less
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