Layered materials, such as graphene, transition metal dichalcogenides and black phosphorene, have been established rapidly as intriguing building blocks for optoelectronic devices. Here, we introduce highly polarization sensitive, broadband, and high-temperature-operation photodetectors based on multilayer germanium sulfide (GeS). The GeS photodetector shows a high photoresponsivity of about 6.8 × 103 A W-1, an extremely high specific detectivity of 5.6 × 1014 Jones, and broad spectral response in the wavelength range of 300-800 nm. More importantly, the GeS photodetector has high polarization sensitivity to incident linearly polarized light, which provides another degree of freedom for photodetectors. Tremendously enhanced photoresponsivity is observed with a temperature increase, and high responsivity is achievable at least up to 423 K. The establishment of larger photoinduced reduction of the Schottky barrier height will be significant for the investigation of the photoresponse mechanism of 2D layered material-based photodetectors. These attributes of high photocurrent generation in a wide temperature range, broad spectral response, and polarization sensitivity coupled with environmental stability indicate that the proposed GeS photodetector is very suitable for optoelectronic applications.
Bibliographical noteFunding Information:
This work was supported by JSPS KAKENHI Grant Numbers JP22740195, JP25400324, JP24681031, JP16H00911, JP15K13337, JP15H05408, JP23340085, JP25610074, and JP16H06331 and by Precursory Research for Embryonic Science and Technology (PRESTO) from the Japan Science and Technology Agency (JST).
© The Royal Society of Chemistry 2017.