Thickness-Dependently Enhanced Photodetection Performance of Vertically Grown SnS₂ Nanoflakes with Large Size and High Production

Abstract

Photodetection based on two-dimensional (2D) SnS has attracted growing interest due to its superiority in response rate and responsivity, but high-quality growth and high performance photodetection of 2D SnS still face great challenges. Here, high-quality SnS nanoflakes with large-size and high-production are vertically grown on an Si substrate by a modified CVD method, having an average size of 30 μm with different thicknesses. Then a single SnS nanoflake-based phototransistor was fabricated to obtain a high current on/off ratio of 10 and excellent performance in photodetection, including fast response rates, low dark current, and high responsivity and detectivity. Specifically, the SnS nanoflakes show thickness-dependent photodetection capability, and a highest responsivity of 354.4 A W is obtained at the average thickness of 100.5 nm. A sensitized process using an HfO nanolayer can further enhance the responsivity up to 1922 A W. Our work provides an efficient path to select SnS crystal samples with the optimal thickness as promising candidates for high-performance optoelectronic applications.

High-performance ultra-violet phototransistors based on CVT-grown high quality SnS2flakes

“…4f), which has also been documented in other research. 54 For a given wavelength range, the photocurrent of photosensitive akes is proportional to the absorption if we consider a constant namely the internal quantum efficiency (h), which can be expressed as…”

Recent advances in low‐dimensional semiconductor nanomaterials and their applications in high‐performance photodetectors

“…C, The responsivity is dependent on the thickness of the SnS 2 nanosheet, where the inset is the corresponding trend of EQE. Reproduced with permission . Copyright 2018, American Chemical Society.…”

“…The performance of PDs is rapidly increasing. For example, PDs constructed using high‐quality SnS 2 nanosheets (Figure A) grown by CVD exhibit high performance (Table ) . For layered materials, thickness has a large impact on device performance.…”

“…For example, PDs constructed using high-quality SnS 2 nanosheets ( Figure 7A) grown by CVD exhibit high performance ( Table 2). 151 For layered materials, thickness has a large impact on device performance. As the thickness increases or decreases ( Figure 7C), the responsiveness of the device changes greatly, and a certain thickness threshold is obtained to obtain the best performance.…”

Balancing Light Absorption and Charge Transport in Vertical SnS2 Nanoflake Photoanodes with Stepped Layers and Large Intrinsic Mobility

“…Several methods of synthesizing vertically oriented SnS 2 nanoflakes on conductive substrates have been reported in the literature such as hydrothermal reaction, chemical vapor deposition (CVD), and close space sublimation (CSS) . However, only a few of these methods have been used to optimize the nanoflakes for photo‐electrochemical applications.…”