Open AccessCharacterizations of bismuth telluride/gallium nitride heterojunction photovoltaic detector for MWIR detection under room temperature
Author(s) -
Meng Pang,
H. F. Lui,
W S Li,
Kam-Fai Wong,
C. Surya
Publication year - 2009
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/152/1/012046
Subject(s) - materials science , optoelectronics , heterojunction , crystallinity , thin film , responsivity , bismuth telluride , band gap , semiconductor , wide bandgap semiconductor , optics , photodetector , nanotechnology , thermoelectric materials , thermal conductivity , physics , composite material
Uncooled infrared detectors have aroused keen interest in narrow bandgap semiconductor research. We propose to use Bismuth Telluride (Bi2Te3) bandgap energy of about 0.15 eV for middle wavelength IR (MWIR) detection. In this work, a heterojunction structure of Bi2Te3/GaN/Al2O3 was fabricated to form a photovoltaic detector. The structural properties of Bi2Te3 thin films were characterized by high resolution x-ray diffraction spectroscopy. Crystallinity of Bi2Te3 thin films was found to be strongly dependent on deposition temperatures. The spectral current responsivity for this heterojunction in NIR-to-MWIR region was evaluated under back-side illumination. The devices were also characterized by studying their low-frequency noise spectra measurement. The experimental results suggest that, the noise level of the devices is correlated to the crystallinity of the Bi2Te3 thin films.Department of Applied PhysicsDepartment of Electronic and Information Engineerin