Rajesh Kumar Ulaganathan, Yi Ying Lu, Chia Jung Kuo, Srinivasa Reddy Tamalampudi, Raman Sankar, Fang Cheng Chou and Yit Tsong Chen
National Taiwan University, Taipei, Taiwan
Academia Sinica, Taiwan
National Central University, Taiwan
Posters & Accepted Abstracts: J Nanomed Nanotechnol
In this paper, we report the optoelectronic properties of multi-layered GeS nanosheets (~28 nm thick)-based field-effect transistors (called GeS-FETs). The multi-layered GeS-FETs exhibit remarkably high photoresponsivity of Rλ~206 AW-1 under illumination of 1.5 μW/cm2 at =633 nm, Vg=0 V and Vds=10 V. The obtained Rλ~206 AW-1 is excellent as compared with a GeS nanoribbonbased and the other family members of group IV-VI-based photodetectors in the two-dimensional (2D) realm, such as GeSe and SnS2. The gate-dependent photoresponsivity of GeS-FETs was further measured to be able to reach Rλ~655 AW-1 operated at Vg=-80 V. Moreover, the multi-layered GeS photodetector holds high external quantum efficiency (EQE~4.0�?104%) and specific detectivity (D*~2.35�?1013 Jones). The measured D* is comparable to those of the advanced commercial Si- and InGaAs-based photodiodes. The GeS photodetector also shows an excellent long-term photoswitching stability with a response time of ~7 ms over a long period of operation (>1 h). These extraordinary properties of high photocurrent generation, broad spectral range, fast response and long-term stability make the GeS-FET photodetector a highly qualified candidate for future optoelectronic applications.