Mr. Jian Liu Profile

Jian Liu

at Nanjing Univ of Science and Technology

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 6 November 2023 Paper

Measurement and analysis of surface photovoltage of GaAlN material with multi-layer structrues

Jian Liu, Yijun Zhang, Yunsheng Qian

Proceedings Volume 12921, 1292155 (2023) https://doi.org/10.1117/12.2692022

KEYWORDS: Spectral response, Aluminum, Quantum efficiency, Light absorption, Photocurrent, Surface plasmons, Electric fields, Magnesium, Cesium, Ultraviolet radiation

Read Abstract +

Three kinds of transmission type GaAlN photocathode materials with GaAlN activation layer/GaAlN absorber layer/AlN buffer layer/Al₂O₃ substrate layer multi-layer structures with different Al compositions were designed and grown. The thickness of the GaAlN activation layer, the GaAlN absorber layer and the AlN buffers layer of the three samples were 40 nm, 20 nm and 100 nm respectively. The Al fraction of the GaAlN activation layer of the three samples were 0.48, 0.37 and 0.25 respectively, and the Al fraction of GaAlN absorber layer were 0.8, 0.68 and 0.3 respectively. An ultraviolet waveband surface photovoltage testing device was developed for the measurement of the characteristics of surface photovoltage of the three GaAlN photocathode materials. The surface photovoltage amplitude curves of the three samples were basically the same under the two cases of frontal and reverse incidence, and the surface photovoltage signals obtained by the two different light incidence methods were differentiated, and the extreme points of the differentiation curves were obtained near the positions of 4.47 eV, 4.21 eV and 3.92 eV respectively, which correspond to the forbidden band width of the GaAlN material in the activation layer of the three samples. Comparing the surface photovoltage curves before activation with the spectral response curves after activation of two samples, it is found that the surface photovoltage curves before activation and the spectral response curves after activation are highly consistent in characteristics of spectral response and cut-off, which proves the effectiveness of surface photovoltage in the evaluation of characteristics of the spectral response of the GaAlN photocathode materials with multi-layer structures.

Proceedings Article | 5 November 2020 Paper

Study on characteristics of GaN epilayers grown on Al2O3 by using surface photovoltage

Jian Liu, Jingzhi Zhang, Ziheng Wang, Yunsheng Qian

Proceedings Volume 11564, 115640G (2020) https://doi.org/10.1117/12.2580380

KEYWORDS: Gallium nitride, Surface plasmons, Interfaces, Doping, Sapphire

Read Abstract +

Three types of gallium nitride (GaN) materials grown on sapphire (001) by metal chemical vapor deposition (MOCVD) were design for the study of different doping types on the characteristics of GaN epilayers. Surface photovoltage (SPV) spectroscopy of samples was measured in the photo energy range 2.9≤hv≤4.5eV with different chopping frequency. The similar surface photovoltage signals were obtained under sub-band-gap illumination in the photo energy range 2.9≤hv≤3.4 eV and the origins about signals were determined by comparing the surface photovoltage magnitude and phase spectra. By changing the incident light frequency, it can be found that the surface photovoltage magnitude shows a downward trend in the entire photon energy range, and the surface photovoltage magnitude has a more significant decrease in the sub-band gap region. In additional, a laser with 3.06eV photo energy was used to aid measured the surface photovoltage signals of sample with Si doped in the photo energy range 2.9≤hv≤4.5eV with chopping frequency at 172 Hz, 440 Hz, 1k Hz and 3k Hz. The defect states at the interface of the undoped GaN layer and Al₂O₃ were proved to be the major contribution to the SPV signals in the sub band gap region and were "slow processes" during the formation of SPV of the GaN samples.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years