Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (8): 2661.doi: 10.7503/cjcu20210154

• Materials Chemistry • Previous Articles     Next Articles

Preparation and Photoelectric Properties of Germanium Sulphoselenide Photodetector

LIANG Xuejing1, ZHAO Fulai1(), WANG Yu1, ZHANG Yichao1, WANG Yaling1, FENG Yiyu1,2, FENG Wei1,2()   

  1. 1.School of Materials Science and Engineering
    2.Key Laboratory of Advanced Ceramics and Machining Technology,Ministry of Education,Tianjin University,Tianjin 300072,China
  • Received:2021-03-08 Online:2021-08-10 Published:2021-04-16
  • Contact: FENG Wei E-mail:ialufhz@163.com;weifeng@tju.edu.cn
  • Supported by:
    the National Key R&D Program of China(2016YFA0202302);the National Natural Science Foundation of China(51633007)

Abstract:

Germanium monochalcogenides are important members of group Ⅳ—Ⅵ semiconductor materials, with abundant reserves, low cost and low toxicity. Due to suitable band gap, high carrier mobility and light absorption coefficient, they have become the ideal choices for sustainable optoelectronic devices. Alloy enginee-ring is an important method for band gap tunning, which can adjust the light absorption range and even suppress the recombination of carriers, thereby improving the performance of photodetectors. In this work, a ternary alloy of germanium sulphoselenide(GeS0.5Se0.5) was synthesized by high-temperature solid-state reaction, and then the nanosheet with a lateral size of ca. 12 μm was prepared by micromechanical exfoliation. With the chromium(10 nm)/gold(120 nm) electrode as the contact electrode, a GeS0.5Se0.5 photodetector was prepared for the first time, and its photoelectric properties were explored. The results show that the nanosheet has good crystalline quality, sulfur and selenium atoms are uniformly distributed, and the optical band gap is 1.3 eV between GeSe(1.1—1.2 eV) and GeS(1.55—1.65 eV). Under 515 nm light excitation, the photodetector exhi-bits a very efficient, fast and stable optoelectronic properties, with a ultra-high specific detectivity(D*) of 4.52×1013 Jones, a high photoresponsivity(Rλ) of 1.15×104 A/W, and an external quantum efficiency(EQE) of 2.79×106%. In short, this research has contributed a very promising new type of ternary semiconductor with a narrow band gap to the field of optoelectronic devices, and provided a certain reference and guidance for the research of high-performance optoelectronic devices.

Key words: Germanium sulphoselenide alloy, Semiconductor material, Micromechanical exfoliation, Photodetector

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