TY - JOUR
T1 - Large-Area Tellurium/Germanium Heterojunction Grown by Molecular Beam Epitaxy for High-Performance Self-Powered Photodetector
AU - Zheng, Beining
AU - Wu, Zehan
AU - Guo, Feng
AU - Ding, Ran
AU - Mao, Jianfeng
AU - Xie, Maohai
AU - Lau, Shu Ping
AU - Hao, Jianhua
N1 - Funding Information:
B.Z. and Z.W. contributed equally to this work. This work was supported by the grants from the National Natural Science Foundation of China (No. 51972279), Science Technology and Innovation Commission of Shenzhen (Project No. JCYJ 20180507183424383), Research Grants Council of Hong Kong (GRF No. PolyU 153023/18P and CRF No. C7036‐17W), and PolyU Grant (1‐ZVGH).
Publisher Copyright:
© 2021 Wiley-VCH GmbH
PY - 2021/10/18
Y1 - 2021/10/18
N2 - As an attractive elemental semiconductor material, p-type tellurium (Te) with a narrow bandgap provides high carrier mobility, strong light–matter interactions in a wide spectral range, and good chemical stability, which enlightens the potential in optoelectronic devices. However, the applications are impeded by weak carrier separation and vague potential in scaling-up. In this work, the integration of Te and conventional semiconductor germanium (Ge) is designed. Through molecular beam epitaxy (MBE) method, large-area and uniform Te films with high crystallinity are directly deposited on the Ge substrates. The difference in work function between Te and Ge layer leads to a built-in electric field, which can effectively enhance the carrier separation. As a result, a self-powered splendid photovoltaic performance is observed in the MBE grown Te/Ge vertical heterojunction with current on/off ratio over 103, responsivity (R) 523 mA W−1, and specific detectivity (D*) 9.50 × 1010 cm Hz1/2 W−1 when illuminated by near-infrared light (980 nm, 2.15 µW cm−2). Furthermore, excellent stability and high response speed of the ultrathin heterostructure offer a significant application value for multipurpose photoelectric devices.
AB - As an attractive elemental semiconductor material, p-type tellurium (Te) with a narrow bandgap provides high carrier mobility, strong light–matter interactions in a wide spectral range, and good chemical stability, which enlightens the potential in optoelectronic devices. However, the applications are impeded by weak carrier separation and vague potential in scaling-up. In this work, the integration of Te and conventional semiconductor germanium (Ge) is designed. Through molecular beam epitaxy (MBE) method, large-area and uniform Te films with high crystallinity are directly deposited on the Ge substrates. The difference in work function between Te and Ge layer leads to a built-in electric field, which can effectively enhance the carrier separation. As a result, a self-powered splendid photovoltaic performance is observed in the MBE grown Te/Ge vertical heterojunction with current on/off ratio over 103, responsivity (R) 523 mA W−1, and specific detectivity (D*) 9.50 × 1010 cm Hz1/2 W−1 when illuminated by near-infrared light (980 nm, 2.15 µW cm−2). Furthermore, excellent stability and high response speed of the ultrathin heterostructure offer a significant application value for multipurpose photoelectric devices.
KW - germanium
KW - heterojunctions
KW - large-area growth
KW - self-powered photodetectors
KW - tellurium
UR - http://www.scopus.com/inward/record.url?scp=85112428196&partnerID=8YFLogxK
U2 - 10.1002/adom.202101052
DO - 10.1002/adom.202101052
M3 - Journal article
AN - SCOPUS:85112428196
SN - 2195-1071
VL - 9
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 20
M1 - 2101052
ER -
