CdS/CdSO₄ Nanoflower-Based Photodetector with Enhanced Photoelectric Performances

Effective engineering of materials with distinctive nanoscale microstructures provides lots of opportunities to explore their underlying photoelectric phenomena deeply. Here, the microstructural and photoelectric characteristics of a CdS/CdSO4 flower-like nanostructure (nanoflower) prepared by a simple chemical route and a following thermal treatment were investigated. A hybrid composition of cubic CdS, hexagonal CdS, and CdSO4 phases was obtained when the thermal annealing was conducted at 480 °C. The conductivity of CdS/CdSO4 nanoflowers was significantly enhanced compared with that of pristine CdS nanoflowers, giving excellent photoelectric performances, such as high photocurrent (∼0.2 μA), photoresponse speed (trise = 2.8 ms, tfall = 14.4 ms), photoresponsivity (∼0.3 A/W), and detectivity (∼6 × 109 Jones). The conductivity gain and substantially high photoresponse speed originated from the improved crystallinity and the realization of a special microstructural defect landscape within the nanoflowers, enriching the photoelectric behavior of CdS series materials as well as the development of low-dimensional optoelectronic devices operating in a large wavelength region.