Plasmon-sensitized SiNWs/SnS2 heterostructures for high-sensitivity photodetector devices

The development of new heterostructures with suitable band alignment and modification of the heterostructure for broadband photodetection and enhanced performance is a recent trend of research. Surface plasmons pave the way for light absorption and exciton generation in photodetectors and other optoelectronic devices. SnS2-based heterostructure devices are being investigated as a promising technology for photodetectors in UV-visible, and partially near-infrared (NIR) wavelength regions, but the device performance is restricted by defects states, low absorption cross section, and less photocarrier generation in SnS2. In this report, we have discussed a simple and convenient way to promote the device performance by increasing absorption cross section and photocarrier generation sites by incorporating Au nanoparticles. The Au-SnS2/Si nanowires (SiNWs) photodetector device shows excellent improvement in photoresponse up to 201% in the UV region, 77% in the NIR region, and most importantly 100% in visible region at −2 V applied bias in comparison to the SnS2/SiNWs photodetector (responsivity ∼145, 22, and 7 A/W in the UV, NIR, and visible region, respectively) with a maximum recorded value of ∼437 A/W at 340 nm. Its excellent performance with a simple and cost-effective fabrication process makes this device distinct from other similar types of structures. Our investigation offers new opportunities to engineer plasmon-sensitized nanodevices for sensors and other optoelectronic device applications.